DAMASCUS, Syria (AP) -- Thousands called for liberty Thursday in the southern Syrian city of Daraa, defying a deadly government crackdown as they took to the streets in funeral marches for protesters killed by police gunfire, an activist said.
The activist in contact with residents of Daraa told The Associated Press that massive crowds shouted "Syria, freedom!" as they marched toward one of the agricultural hub's main cemeteries.
Others in Daraa held a sit-in to protest the killing of 15 people in clashes between security forces and anti-government protesters, the activist said.
The situation in Daraa was still tense, with a heavy armed presence in the streets as dozens of people demonstrated in the al-Mahata neighborhood near the city center.
Inspired by the wave of pro-democracy protests around the region, the uprising in Daraa and at least four nearby villages has become the biggest domestic challenge since the 1970s to the Syrian government, one of the most repressive in the Middle East. Security forces have responded with water cannon, tear gas, rubber bullets and live ammunition.
Syrian police launched a relentless assault Wednesday on a neighborhood sheltering anti-government protesters, fatally shooting at least 15 in an operation that lasted nearly 24 hours, witnesses said. The total death toll now stands at 22.
A statement posted Thursday on the Facebook page "The Syrian Revolution 2011" held Syrian authorities led by President Bashar Assad responsible for the violence and called on the Syrian people to hold protests in all Syrian provinces on Friday, which it dubbed "Dignity Friday."
An official at the Daraa National Hospital told The Associated Press by telephone that the hospital received a large number of casualties Wednesday and was "overwhelmed" with wounded people. He declined to say how many people were dead or hurt, saying he was not authorized to give out numbers or talk to the press.
He said the hospital had not received any new casualties since Wednesday night and that Daraa was "very quiet this morning."
Videos posted by activists on Youtube and Twitter showed dead and wounded people lying on a street in Daraa, as heavy gunfire crackled nearby and people shouted in panic.
One video showed a man with a bloodied face, apparently shot in the head, raising his index finger and saying "There is no God but Allah" -- the credo Muslims are required to say before they die.
The authenticity of the videos could not be independently confirmed.
In a tacit admission that the protests hitting the Arab world have reached Syria, Vice President Farouk al-Sharaa said in remarks carried by state-media that "the developments in the Arab world should should be a catalyst to build nations and not for undermining national unity."