Beirut: Syrian security forces opened fire on hundreds of protesters on the outskirts of the capital yesterday as thousands of people joined demonstrations across the country calling for an end to President Bashar Al Assad's regime, witnesses and activists said.

It was not immediately clear if there were casualties.

Undaunted by a bloody crackdown on the seven-week-old uprising, protesters held rallies in major areas including the capital, Damascus, and its suburbs, the central city of Homs, Baniyas 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.

Witnesses also reported some of the tightest security seen since the protests began in mid-March. 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.

Olive branches

Another activist in Damascus said hundreds of people marched in the central neighbourhood of Midan. In the coastal town of Baniyas, witnesses said more than 5,000 people carrying olive branches and Syrian flags also were calling for regime change.

They were among several demonstrations and marches planned for Friday, the main day of protests in the Arab world, for what activists were calling a "Day of Defiance".

More than 565 civilians and 100 soldiers have been killed since an anti-regime uprising, inspired by revolts in Tunisia and Egypt, began in March, according to rights groups.

The activists said security forces set up checkpoints and closed some areas that experienced protests in recent weeks. In the southern city of Daraa, where the army announced the end to an 11-day military operation Thursday, residents said troops were still in the streets, causing some would-be demonstrators to be wary of taking part in a planned protest yesterday.

"There's a tank stationed at each corner in Daraa. There is no way people can hold a protest today," a resident said by telephone. "It means more killing. Daraa is taking a break. We don't want to see more killing or face tank guns."

The activists spoke on condition of anonymity for fear of government reprisals.