Syrian forces fired shots at hundreds of protesters who had gathered overnight in Homs city in defiance of warning by the authorities to halt what they called an insurrection, a rights campaigner said on Tueday.

A member of the security police addressed the protesters at Clock Square through a loud speaker asking them to leave, and then the forces opened fire, said the human rights campaigner, who is in contact with protesters in the square.

Two residents of Homs said they also heard the sound of gunfire coming from around the square.

Al Jazeera's Bernard Smith has more.