Syrian forces bombarded Homs on Saturday, a day after twin bombings killed 28 people in Aleppo in the worst bloodshed yet in Syria’s second city.In Damascus, gunmen shot dead a senior military doctor, in what authorities described as the highest-level assassination in the capital in nearly one year of anti-government unrest. Authorities blamed “an armed terrorist group” for killing Brigadier- General Issa al-Khouli, whom they described as a doctor and hospital director.Reuters contributed to this report.On the diplomatic front, President Bashar Assad’s ally Russia said it would not support an Arab peace plan circulating at the United Nations. A week ago, Russia and China vetoed a draft UN Security Council resolution sponsored by Western and Arab states that backed an Arab League call for Assad to step down.Irwin Cotler, a Canadian member of parliament who has advocated tougher measures against the Assad regime, said that in dealing with Syria, the circumstances leading to intervention in Kosovo can be instructive.“There is the Kosovo precedent, when at the time Russia was also vetoing UN Security Council resolutions, even though there was a preponderant majority in favor of intervention.There was a ‘principled coalition of the willing’ that did intervene and saved thousands of lives,” he said.Cotler said the overwhelming Security Council support for a resolution condemning Assad represents a solid diplomatic basis for greater intervention in Syria.“Thirteen Security Council members voted in favor of the resolution – not only the US and Western countries, but the Arab League and Turkey,” Cotler, Canada’s former justice minister and attorney general, told The Jerusalem Post from Ottawa.“What was done in Libya seems, in moral and legal terms, warranted now in Syria. I’m not saying there should be the same kind of NATOArab League bombing, but there could at least be a no-fly zone or no-drive zone.”Syrian activists said seven people were killed in the latest attacks in a week-long government siege of Homs, which has been at the heart of the uprising which broke out 11 months ago.On Friday, twin bombings targeting security bases killed at least 28 people in Aleppo and rebel fighters battled troops in a Damascus suburb after dark.The bombings in Syria’s second city were the worst attack to hit the country’s commercial hub during the anti- Assad revolt. Mangled bodies and severed limbs lay on the pavement outside the military and security-service buildings that were targeted – as shown in live footage on Syrian television, which has consistently portrayed the revolt against Assad as the work of foreign-backed “terrorists.”No one claimed responsibility for the Aleppo bombings, but they took place as Assad’s forces grow more ferocious in operations to crush the uprising. Some opposition figures accused the government of manipulating events to discredit them.“I condemn in the strongest terms these acts perpetrated by the Syrian regime against its own civilians,” EU Foreign Policy chief Catherine Ashton said. Assad has ignored repeated international appeals, the latest from the EU, to halt his crackdown.With Syria in worsening turmoil, Saudi Arabia has circulated a new draft for the General Assembly similar to the earlier one. But Russian Deputy Foreign Minister Gennady Gatilov said on Saturday Moscow could not support a move at the UN General Assembly resting on “the same unbalanced draft resolution text.”The diplomatic dispute brings no relief to Homs, where the government offensive on mostly Sunni Muslim rebel-held areas has killed at least 300 people in the past week, activists say.Food and medical supplies are running low in blockaded areas and many people are trapped in their houses.Security forces have also made house-to-house raids in Homs in the last two days. The bodies of three people shot by snipers were pulled from the streets on Saturday, activists said.YouTube footage from Friday showed two tanks said to be on the edge of Bab Amro, one firing its main gun across a highway.“The indiscriminate shelling is killing mostly civilians,” said Fawaz Tello of the opposition Syrian National Council, arguing that Assad wanted to avoid pushing his troops into street fighting and was banking on the bombardment to force rebel fighters to withdraw.The Syrian Observatory for Human Rights said 10 soldiers were killed in an ambush by army defectors using roadside bombs and hand grenades on Friday in the rebellious Idlib region.The British-based Observatory also reported three people killed in bombardments of the opposition stronghold of Zabadani.In Douma, south of Damascus, an officer and eight soldiers defected along with a tank after clashes between army deserters and security forces, it said.The UN assembly is due to discuss Syria on Monday and vote later in the week on the draft resolution, which “fully supports” an Arab League plan floated last month.The Arab League will meet in Cairo on Sunday to discuss the idea of a joint Arab-UN monitoring mission for Syria.Syrian authorities told Libya and Tunisia to close their embassies in Damascus within 72 hours, a foreign ministry spokesman said Saturday, after the two North African countries announced similar measures against the Assad government.Highlighting the danger of the conflict spilling over borders, supporters and opponents of Assad fought in the streets of Lebanon’s northern city of Tripoli on Saturday, a security source said. Two people were killed and eight wounded, some of them soldiers who had been deployed to halt the fighting.