Ukraine Deputy Prime Minister Iryna Vereshchuk said that nine humanitarian corridors had been agreed for Tuesday to evacuate civilians, including from the besieged city of Mariupol by private cars.
Vereshchuk said in a statement that five of the nine evacuation corridors were from Ukraine's Luhansk region in the east of the country, which Ukrainian officials have said is under heavy shelling.
A total of 4,354 people were evacuated from Ukrainian cities through humanitarian corridors on Monday, including 556 from Mariupol, according to Vereshchuk.
Fighting to intensify
Fighting in eastern Ukraine will intensify over the next two to three weeks as Russia continues to refocus its efforts there, the UK's Ministry of Defense tweeted in a regular bulletin on Tuesday.
Russian attacks remain focused on Ukrainian positions near Donetsk and Luhansk with further fighting around Kherson and Mykolaiv and a renewed push towards Kramatorsk, British military intelligence said.
The report also said that Russian forces continue to withdraw from Belarus in order to redeploy in support of operations in eastern Ukraine.
Poisonous substance used in Mariupol
A poisonous substance of unknown origin was used against Ukrainian military and civilian targets, Kyiv City Council deputy Alina Mykailova quoted "defenders of Mariupol" as saying.
According to the unconfirmed report, cases of respiratory failure and vestibulocerebellar syndrome (vestibulocerebellar ataxia) were recorded in the city. The report is being clarified.
UK Foreign Secretary Liz Truss and Armed Forces Minister James Heappey commented on the report.
"Reports that Russian forces may have used chemical agents in an attack on the people of Mariupol. We are working urgently with partners to verify the details. Any use of such weapons would be a callous escalation in this conflict and we will hold Putin and his regime to account," Truss wrote on Twitter.
"There are some things that are beyond the pale, and the use of chemical weapons will get a response and all options are on the table for what that response could be," Heappey told Sky News.
Putin and Lukashenko to meet
Russian President Vladimir Putin is scheduled to meet Belarusian President Alexander Lukashenko on Tuesday to discuss the situation in Ukraine and Western sanctions, news agencies in Russia and Belarus reported. Belarus is a key staging area for Russian forces.
Lukashenko arrived early on Tuesday in the Amur region in the Russian Far East where he is to meet Putin at the Vostochny Cosmodrome, a Russian spaceport, Belarusian Belta news agency reported.
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April 12th is celebrated in Russia and some other former Soviet countries as the Cosmonautics Day, commemorating the first manned space flight made in 1961 by the Russian Soviet cosmonaut Yuri Gagarin.
Russian Foreign Minister Sergei Lavrov said Moscow would not pause the fighting for any new round of peace talks, which last convened on April 1.
The United States has sought to pressure Putin to withdraw his forces by banning Russian oil and gas and encouraging allies to follow suit.
But world powers including China and India have refrained from sanctioning Russia. Lured by steep oil discounts, India has purchased more Russian crude since the start of the February 24 invasion than it did for the whole of last year, data compiled by Reuters shows.
In a video call, US President Joe Biden told Indian Prime Minister Narendra Modi "very clearly that it is not in their interest" to increase reliance on Russian energy, White House spokesperson Jen Psaki said.
During a brief portion of the call open to reporters, Modi said he had suggested in recent talks with Russia that Putin and Zelenskiy hold direct negotiations.
Supplying arms to Ukraine
Military equipment maker Rheinmetall is preparing to supply up to 50 used Leopard 1 battle tanks to Ukraine, the Handelsblatt newspaper reported on Monday, citing the group's CEO.
Rheinmetall could deliver the first tanks in six weeks and the rest over the following three months through its subsidiary Rheinmetall Italia if it gets a green light from the German government, Chief Executive Armin Papperger told the newspaper.
Papperger said Ukrainian soldiers could be trained on the Leopard 1 within a few days if they are already skilled military personnel.
Handelsblatt reported that politicians from Germany's coalition government, made up of Social Democrats, the Greens and Free Democrats, and are open to a possible delivery of the Leopard tanks, the newspaper reported.
Economy Minister Robert Habeck said on Monday weapons from Germany for Ukraine should be delivered quickly because Russia's attack from the east is imminent.
"With the decision to support Ukraine with weapons, Germany made an obligation," Habeck said
'Tens of thousands killed in Mariupol' - Zelensky
Russian forces' prior use of phosphorous munitions in the Donetsk separatist region raises the possibility of their future employment in Mariupol as fighting for the city intensifies, British military intelligence said.
The report said that Russia's continued reliance on unguided bombs decreases its ability to discriminate when targeting and conducting strikes and greatly increased the risk of further civilian casualties.
Tens of thousands of people have been killed in Russia's assault on the southeastern city of Mariupol, Ukrainian President Volodymyr Zelensky said on Monday.
"Mariupol has been destroyed, there are tens of thousands of dead. But even despite this, the Russians are not stopping their offensive," Zelensky said in a video address to South Korean lawmakers.
Fighting continues in separatist regions
Russian shelling has continued in the Donetsk and Luhansk regions, with Ukrainian forces repulsing several assaults resulting in the destruction of Russian tanks, vehicles and artillery equipment, the UK's Ministry of Defence tweeted in a regular bulletin on Monday.
Serhiy Gaidai, the governor of the Luhansk region in Ukraine's east, said infrastructure including food stores had been targeted by Russian "informants," also without providing evidence. Reuters could not confirm the claims.
“It is likely that the enemy, in order to disrupt the supply of goods to the places of hostilities, will continue to strike at transport infrastructure facilities in Ukraine in order to destroy or disable them,” the general staff of Ukraine's armed forces said.
Russian offensive continues
Russian forces were continuing their offensive to establish full control over the southern city of Mariupol, seeking to storm an iron and steel plant and the seaport.
Explosions were seen in the Kharkiv Oblast and air sirens were heard in Kyiv, Dnipro, Poltava and Zaporizhzhia overnight and into Monday morning. Additionally, explosions were recorded in Mykolaiv
Ukrainian forces carried out strikes against the Petrovsky district of the Donetsk separatist region, Russian news agency RIA reported.
According to a Monday morning update from the Ukrainian Armed Forces, Russian losses from the beginning of its invasion of Ukraine tally at 19,500.
Is Russia looking to Transnistria as an offensive launchpad?
Russia might also carry out provocative actions in the Transnistrian region of the Republic of Moldova in order to accuse Ukraine of aggression against a neighboring state, Ukraine's general staff said, without providing evidence.
Sergey Bratchuk, the Odesa region spokesman added on Monday that Ukrainian intelligence was well aware of Russian military personnel stationed in Transnistria on the border with Moldova.
Evacuating refugees from Ukraine
On Sunday, approximately 70,000 Ukrainian refugees passed through the Moldovan and EU borders to safety, according to a Monday morning update from Ukraine's Border Guards. An additional 27,000 crossed through Poland.
Iryna Vereshchuk, the deputy Prime Minister of Ukraine, announced the establishment of nine humanitarian corridors for evacuation.
Russian Gas continues its route to Europe via Ukraine
Russian state-owned gas producer Gazprom continued to supply natural gas to Europe via Ukraine on Monday in line with requests from European consumers, the company said.
Gazprom said requests stood at 94.9 million cubic meters for April 11, in line with an earlier report by Interfax news agency, which cited data from Ukraine's gas pipeline operator.