Syrian security forces have killed at least 11 more people during mass protests against President Bashar al-Assad.

Hundreds of thousands of anti-government demonstrators rallied Friday for President Assad's resignation, in what has become the most serious challenge to his 11-year rule.

Witnesses and activists say six of the deaths occurred in areas including the Damascus suburbs, northwestern Idlib province and the flashpoint city of Homs.

Reports say at least five other people were killed in Homs overnight, after the military launched a huge crackdown in the city.

Syria deployed security forces in Damascus Friday ahead of planned anti-government protests.

Meanwhile, activists say security forces used batons and tear gas to push back demonstrators in mostly Kurdish Hasaka province on Friday.

There were reports of demonstrations in other cities, including Dara'a and Latakia.

State-run news reports say supporters of Mr. Assad have unfurled Syrian flags and rallied in several cities.

Separately, France condemned Syria for what it called “repression” and the continued arrests and killings of civilians. The Foreign Ministry issued a statement Friday after Syria prohibited French and U.S. envoys from traveling outside of Damascus without permission.

The two ambassadors angered Syrian officials earlier this month when they traveled to Homs to show solidarity with residents.

It is hard to verify accounts of the violence in Syria because its government has barred foreign media from reporting and traveling freely in the country.