International condemnation is growing as the uprising enters its seventh week with no end in sight. On Friday, U.N. Secretary-General Ban Ki-moon said Syria has agreed to allow U.N. teams to enter the country and check the humanitarian situation there.
Syrian authorities also detained Riad Seif, a leading opposition figure and former lawmaker who has been an outspoken critic of the regime during the seven-week uprising, according to the Syrian Observatory for Human Rights.
"We were chanting, peaceful, peaceful, and we didn't even throw a stone at the security forces," said a witness in the central city of Homs, who said some 10,000 people were in the streets. "But they waited for us to reach the main square and then they opened fire on us."
He said gunshots rang out even after the protesters dispersed.
"The bullets are like rain," he said. "Everyone is terrified."
The protesters turned out Friday despite a bloody crackdown on the uprising and some of the tightest security seen since the protests began in mid-March. More than 565 civilians and 100 soldiers have been killed since the revolt began, rights groups say.
"Syria's authorities think that they can beat and kill their way out of the crisis," said Sarah Leah Whitson, Middle East director at Human Rights Watch. "But with every illegal arrest, every killing of a protester, they are precipitating a larger crisis."
Five people were killed Friday in Homs and one was killed in Hama, said a senior member of a human rights group that compiles death toll figures in Syria. Like most activists and witnesses who spoke to The Associated Press, he asked that his name not be used out of fear for his safety.
Footage posted on YouTube showed protesters in Hama frantically trying to resuscitate a man lying on the ground with a bloodied face and shirt, while people shouted "God is great!"
Rallies were held in major areas including the capital, Damascus, and its suburbs, Homs, Banias on the coast and Qamishli in the northeast.
"The people want to topple the regime!" protesters shouted, echoing the cries heard during the revolutions in Egypt and Tunisia.
In the Damascus suburb of Douma, scene of intense protests over recent weeks, security forces cordoned off the area to prevent anyone from entering or leaving.
A witness near Douma said he saw a train carrying about 15 army tanks heading north Thursday evening toward the central province of Homs, another site of recent violence.
Another activist in Damascus said hundreds of people marched in the central neighborhood of Midan. In Banias, witnesses said more than 5,000 people carrying olive branches and Syrian flags also were calling for regime change.
"Our morale is high, they cannot stop us no matter what they do and how many people they arrest," he said.
In the southern city of Daraa, where the army announced the end to