More than 70 Ukrainian servicemen were killed when Russian troops shelled a military base in the town of Okhtyrka in Ukraine's northeastern Sumy region, in what is believed to be the greatest loss of life in a single incident in the war.
Ukrainian presidential advisor Oleksiy Arestovych said Russian forces were trying to lay siege to Kyiv and to Kharkiv in the northeast, the country's second-largest city.
At least 10 people were killed and 35 wounded on Tuesday in rockets strikes by Russian forces on the center of Kharkiv, Ukraine's second-largest city, Interior Ministry adviser Anton Herashchenko said in a post on social media.
"The rubble is being cleared and there will be even more victims and wounded," he said.
At least 136 civilians have been killed, including 13 children, and 400 have been injured since Russia invaded Ukraine last week, a United Nations agency said on Tuesday.
"The real toll is likely to be much higher," Liz Throssell, a spokesperson for the U.N. human rights office (OHCHR), told a briefing, adding that 253 of the casualties were in the Donetsk and Lugansk regions in eastern Ukraine.
The U.N. World Food Program is scaling up activities in Ukraine so that it can support up to 3.1 million people, WFP spokesperson Tomson Phiri said, adding: "Food supplies are running low."
Russian troops fired artillery at Kyiv, Kharkiv and the southern port city of Mariupol overnight while the Ukrainian side shot down Russian military planes around the capital, Arestovych said in a televised briefing.
He described the current situation as under control.
An adviser to Ukrainian President Volodymyr Zelensky said on Tuesday that Russia was deliberately shelling cities, including residential areas and civilian infrastructure, to spread panic among Ukrainians.
"The veil has come down. Russia is actively shelling city centers, launching direct missile and artillery strikes on residential areas and administration sites," Mykhailo Podolyak said.
"Russia's goal is clear - mass panic, civilian casualties and damaged infrastructure. Ukraine is fighting honorably."
Russia calls its actions in Ukraine a "special operation" that it says is not designed to occupy territory but to destroy its southern neighbor's military capabilities and capture what it regards as dangerous nationalists.
Kharkiv region head Oleg Synegubov said on Tuesday that Russian missile attacks hit the center of Ukraine's second-largest city, including residential areas and the city administration building.
Synegubov said Russia launched GRAD and cruise missiles on Kharkiv and was guilty of war crimes. He said the city defenses were holding.
The recent shelling of Kharkiv by Russian forces is a war crime, Zelensky said as the conflict stretched into its sixth day on Tuesday.
The Ukrainian president called for a no-fly zone for Russian missiles, planes and helicopters, though he did not specify how this would be enforced. Washington has firmly declined a Ukrainian request for the West to impose a no-fly zone to shield Ukraine from Russian airstrikes - a step that would bring Western forces into direct conflict with the Russian military.
Zelensky argued that Russia has committed war crimes in Ukraine, specifying that the artillery shelling of the city of Kharkiv constituted targeting of civilians. Six people were injured in the strike, including one child, according to a report from The Kyiv Independent.
The mayor of Mariupol said on Tuesday morning the southern port city was under constant shelling that had killed civilians and damaged infrastructure.
"We have had residential quarters shelled for five days. They are pounding us with artillery, they are shelling us with GRADS, they are hitting us with air forces," Vadym Boichenko said in a live broadcast on Ukrainian TV.
"We have civilian infrastructure damaged - schools, houses. There are many injured. There are women, children killed."
According to Ukraine's Ambassador to the US Oksana Markarova, Russian forces used an illegal weapon known as a vacuum bomb against Ukraine.
"They used the vacuum bomb today, which is actually prohibited by the Geneva convention," Markarova said after briefing members of the US Congress. "The devastation that Russia is trying to inflict on Ukraine is large."
A vacuum bomb uses oxygen from the surrounding air to generate a high-temperature explosion, typically producing a blast wave of a significantly longer duration than that of a conventional explosive.
Russia is waging war in violation of international humanitarian law. Kills civilians, destroys civilian infrastructure. Russiaʼs main target is large cities that now fired at by its missiles.Kharkiv, Administration building pic.twitter.com/BJgyNnDp1h
— MFA of Ukraine (@MFA_Ukraine) March 1, 2022
In addition, Amnesty International and Human Rights Watch both said that Russian forces appeared to have used widely banned cluster munitions, with Amnesty accusing them of attacking a preschool in northeastern Ukraine while civilians took shelter inside.
Amnesty said international humanitarian law prohibits the use of inherently indiscriminate weapons such as cluster munitions. Launching indiscriminate attacks that kill or injure civilians constitutes a war crime.
White House Press Secretary Jen Psaki said she had seen reports but did not have confirmation that Russia had used such weapons. "If that were true, it would potentially be a war crime," she told a press briefing, noting that there are international organizations that would assess that and President Joe Biden's administration "would look to be a part of that conversation."
The Russian embassy in Washington did not respond to requests for comment.
Any state that has committed war crimes should not be allowed to be a permanent member of the United Nations Security Council, Zelensky said.
"Dozens of eyewitness accounts" indicated that this was a targeted attack of a residential area without military facilities, the president said, according to the New Voice of Ukraine news outlet. "The Russians knew where they were shooting," he said, adding that "No one in the world will forgive you for killing peaceful Ukrainian people."
This comes after the International Criminal Court said that it might investigate any war crime committed in Ukraine.
About 350,000 people have entered Poland from Ukraine since Russia invaded the country six days ago, a Polish deputy interior minister said on Tuesday.
"Over the last 24 hours, 100,000 people crossed the Polish-Ukrainian border," Maciej Wasik told public broadcaster Polskie Radio 1. "In total, since Thursday, there have already been 350,000 refugees."
Military developments
Russia's advance on Kyiv has made little progress in the past 24 hours due to logistical difficulties, with the army increasing its use of artillery north of the capital, a British military intelligence update said.
"The Russian advance on Kyiv has made little progress over the past 24 hours, probably as a result of continuing logistical difficulties," the British defense ministry said in a military intelligence update.
"Russian forces have increased their use of artillery north of Kyiv and in [the] vicinities of Kharkiv and Chernihiv. The use of heavy artillery in densely populated urban areas greatly increases the risk of civilian casualties," it said.
"Russia has failed to gain control of the airspace over Ukraine, prompting a shift to night operations in an attempt to reduce their losses."
Satellite images taken on Monday show a Russian military convoy north of the Ukrainian capital of Kyiv that stretches for about 40 miles (64 km), substantially longer than the 17 miles (27 km) reported earlier in the day, according to Maxar Technologies.
Ukraine cut communications for Russian cellphone numbers in the country, according to the Derzhspetszviazok – the State Service of Special Communications and Information Protection of Ukraine, the country's intelligence and technical security service.
In addition, Ukraine will allow foreigners traveling to the country to help fight against Russia to do so without a visa, according to a new decree signed by the president that went into effect Tuesday.
The decree allows all foreigners hoping to join the new unit for foreign volunteers, known as the International Legion of the Territorial Defense Force, to enter– with the exception of those coming from Russia.
The new unit for foreign volunteers was announced on Sunday, with Ukrainian authorities having said the next day that thousands have already applied to join.
Some young volunteers are traveling straight to Ukraine to enlist.
Others are applying at Ukrainian embassies and consulates before quitting jobs or dropping out of university. Full story here.
Negotiations
Turkish President Tayyip Erdogan's office said early on Tuesday that he held a phone call with his Belarusian counterpart Alexander Lukashenko to discuss developments in Russia's invasion of Ukraine.
The two premiers discussed ceasefire talks between Russia and Ukraine, according to Erdogan's office. The talks failed to reach a breakthrough on Monday, and negotiators have not said when a new round would take place.
Erdogan's office said that Erdogan told Lukashenko that Turkey will continue to make efforts to stop the war and restore peace. Russia calls its actions in Ukraine a "special operation."
Zelensky said the negotiations between Russia and Ukraine were conducted against the background of Russian bombardments into Ukrainian territory.
The fact that these two events took place at the same time, Zelensky said, was no coincidence, accusing Moscow of doing it intentionally, according to The New Voice of Ukraine.
"Don't waste your time, we don't accept this tactic," Zelensky said, according to NV. "Fair negotiations can only happen when one side doesn't hit the other with artillery during negotiations."
Regarding the points brought up in the talks themselves, Ukraine's president said that he would go over what was discussed with the Ukrainian delegation when they return to Kyiv so they can decide how to move forward when the second round of negotiations begins, according to Ukrainian media.
Diplomacy
Ukraine has made an effort to reach out to the West repeatedly during the conflict, including Europe.
Zelensky officially applied on Monday to join the European Union, with the application being on its way to Brussels for processing, Ukrainian President's Office deputy head Andrij Sybiha wrote on Facebook.
In response, the heads of state for eight different EU member states – Bulgaria, Estonia, Lithuania, Latvia, Poland, Slovakia, Slovenia and the Czech Republic – pushed for immediately admitting Ukraine into the bloc.
This follows Slovakian Prime Minister Eduard Heger telling Politico that Ukraine should have a "special track" towards EU membership.
Energy ministers from European Union countries on Monday agreed to urgently link a European power system to Ukraine's grid, a move that would increase its independence from Russia.
Ukraine disconnected its grid from a Russian system last week and has asked for emergency synchronization with a European system. That would mean Russia would no longer control technical aspects of Ukraine’s network such as grid frequency. EU officials said the link could be completed within weeks. Full story here.
Sanctions, economy and corporate reactions
The financial impact of the conflict, international reaction to it from businesses and Western sanctions has been noted in analyses of the Russian economy.
The Council of the European Union sanctioned 26 individuals over Russia's aggressive actions in Ukraine, including noted Russian-Israeli billionaire Mikhail Fridman.
The rouble stabilized somewhat on Tuesday after its crash to an all-time low, while the safe-haven yen and Swiss franc were steady after their biggest rallies in almost seven weeks with traders focused squarely on the developing crisis in Ukraine.
This impact was also felt by Russian companies, with many of Russia's key companies taking hits.
Ukrainian Foreign Minister Dmytro Kuleba said on Tuesday morning that US Secretary of State Antony Blinken had offered his country more support in the form of sanctions and weapons.
A stream of Western companies pulling out of Russia is expected to grow on Tuesday, as corporations and investors across industries follow the lead of energy firms BP and Shell, which abandoned multi-billion-dollar positions after the invasion of Ukraine.
Three major Hollywood studios, Disney, Sony and Warner Bros., said they would pause theatrical releases of upcoming films in Russia in response to its invasion of Ukraine and the unfolding humanitarian crisis.
The impact has also been felt in sports.
International football governing body FIFA has expelled Russia from competing in the World Cup, with Moscow's business partnerships with the NFL – America's US hockey league – being discontinued. Russia and Belarus – which is supporting the invasion – are being sanctioned by the International Ice Hockey Federation, which is banning both nations from upcoming world championship tournaments. Full story here.
This is a developing story.