Syrian security forces have had a deadly clash with rock-throwing residents near the eastern town of Deir el-Zour.

Activists and witnesses say at least three people were killed during the confrontation on Saturday after Syrian forces opened fire on residents.

Earlier Saturday, activists said at least five people were killed as security forces conducted overnight raids in an apparent crackdown on dissent.

They said forces moved into a Damascus suburb and opened fire on civilians. The Associated Press says a similar raid took place in the eastern town of al-Boukamal.

The incidents took place a day after thousands of Syrians massed across the country and renewed calls for President Bashar al-Assad's resignation.

Security forces have been stepping up their response to the anti-government protests, which have become a weekly ritual. Activists say at least 19 people were killed by security forces on Friday.