President Bashar Assad said Syria would defeat opponents "no matter the cost."
Mass burials in Daraya, a poor Sunni community on the southwest outskirts of the capital, Sunday showed scores of bodies a day after Syrian troops stormed the city of several hundred thousand, going door to door in what the Assad regime described as a counter-terrorism "cleansing" that killed more than 200 civilians.
"The Assad forces killed them in cold blood," Daraya resident Abu Ahmad, 40, told The New York Times.
The opposition Free Syrian Army claimed responsibility for shooting down the military helicopter, saying it had fired at people in the northeast district of Jobar and crashed in Qabun near Damascus, Gulfnews.com said. Syrian state television later confirmed the crash, the Web site said. Videos of a crash were posted on YouTube.
Syrian Vice President Farouq al-Shara made a public appearance Sunday, ending speculation he had defected from the Assad government. It was the first time in more than a month he was seen in public.
Israeli television networks broadcast footage from Syria's state television showing al-Shara in a meeting. He refused to speak with reporters. Israel's Channel One said al-Shara's reappearance questions the validity of reports released by Syrian opposition groups seeking to oust Assad.
Earlier this month speculation concerning his defection mounted after Assad, accompanied by government ministers, was seen at a Damascus mosque without al-Shara at his side. Al-Shara, 73, is the most powerful Sunni Muslim figure in the minority Alawite-led Assad regime and has served in high-ranking government posts for nearly 30 years, Lebanon's Star reported.
Assad was quoted by the state-run Syrian Arab News Agency Sunday as saying Syria's unrest was "not just a plot directed against Syria but against the region as a whole, of which Syria is a foundational stone."
Assad has alleged the uprising against his rule is actually a Western-backed plan to crush his regime.
"The Syrian people will not allow this plan to reach its goals, no matter the cost," he said.
Residents of Daraya described to the Times, one of the few Western news organizations that managed to enter, how the Syrian army first closed off the city so civilians couldn't flee, then began heavy shelling and house-to-house searches ending with executions.
The exact number killed and whether they were executed or died from shelling was difficult to verify.
Two activist networks -- the Local Coordination Committees of Syria and the Syrian Observatory for Human Rights -- said more than 200 bodies were found.
Activists said another 15 bodies were discovered in the basement of a home. An activist video purporting to confirm the discovery that was posted on YouTube and monitored by United Press International showed blood-covered bodies, some with clearly apparent bullet holes, lying in pools of blood in the corner of a concrete-floor basement.
The Local Coordination Committees said early Monday 675 people were killed in the city in the past week, including more than 300 people reported executed.
The raid by Syrian troops backed by tanks and pickup trucks with mounted machine guns began at midweek after troops initially surrounded Daraya to block food and other supplies from entering, residents told the Times.
Before the troops stormed the city, the electricity was cut, then the Internet and phone service, the residents said.
The Syrian shock or assault troops were supported by Alawite paramilitary semi-criminal militia gangs known as shabiha, or thugs, the residents said.
The Free Syrian Army said it held the Assad forces back at first but the Syrian military gained control of most of Daraya by late Friday or early Saturday.