Damaged buildings are seen after gunmen stormed the headquarters of Al-Ikhbariya news channel near Damascus
Syrian forces swept through the corpse-strewn streets of nearly-deserted opposition districts on the outskirts of the capital on Sunday, as the conflict enters a new phase of heavier fighting near Bashar al-Assad's seat of power.
Government troops also bombed and shelled other towns across the country, a day after Russian diplomats rode again to Assad's rescue, blocking language at a meeting of world powers that would have called on the president to leave power, reports Reuters.
Sixteen months into an uprising against Assad in which more than 10,000 people have been killed, intensive fighting and shelling has now reached the outskirts of Damascus. New tension has also built up on the frontier with Turkey in recent days after Syrian forces shot down a Turkish jet.
Residents of the Zamalka district on the capital's outskirts were struggling on Sunday to bury dozens of people killed the day before in a mortar attack on an anti-Assad march, opposition activist Susan Ahmad said by phone from the Damascus suburbs.
More than 40 people were killed in the attack on Saturday when security forces fired a mortar bomb into a funeral procession in Zamalka for a man who had been killed in shelling, activists said.
"It is really bad today across Damascus," said Ahmad. "Zamalka was like a massacre, but we couldn't bury all of the martyrs as it is dangerous to be out on the streets and we can't treat the wounded. There is no medicine."
Government troops were raiding Zamalka and Douma, a town of half a million people on the outskirts of Damascus that now stands almost empty after siege and shelling as the army tried to root out rebels, she said.
"Douma is completely destroyed," said Ahmad. "If you go to Douma you can smell the bodies. It's really like a ghost city."
On Saturday, Free Syrian Army fighters fled the town and residents said they feared a massacre at the hands of troops entering it.
Turkey said on Sunday it had scrambled F-16 fighters near the frontier the previous day in response to three separate incidents after Syrian helicopters approached the border.
Turkey, a NATO member that has turned against Assad and allowed its territory to become a rear base for rebels, has mobilised since Syrian forces shot down one of its jets 10 days ago. It sent forces towards the border this week and said it would treat Syrian troops approaching the frontier as hostile.
Top level diplomacy has so far been futile, and a much-anticipated meeting in Geneva on Saturday showed that Western and Arab states had yet to persuade Russia and China to drop support for Assad.
The two countries have repeatedly used veto power at the U.N. Security Council to block calls for Assad to leave power.
The meeting, convened by peace envoy Kofi Annan, agreed that Syria should seek a transitional unity government, but Moscow and Beijing successfully blocked language that would have suggested the new arrangement should exclude Assad.
Western officials say the text agreed at the talks - billed as a last-ditch effort to halt the worsening violence - still implies indirectly that Assad should stand down, but Moscow says it does no such thing.