Syrian tanks shelled Hama city in the early hours of Tuesday, an activist said, and tanks continued to patrol the streets on the day President Bashar al-Assad has agreed to start withdrawing forces from urban areas.

"At 2 a m we heard two shells fall and the sound of tanks moving around the streets," said Manhal Abu Bakr, an activist and citizen journalist. "There is no gunfire now. They shell us at night so that it is hard to film," he said over Skype.

Internet video footage, which Abu Bakr said was filmed in Hama overnight, showed nighttime explosions in a built-up area.

In Douma, a suburb of the capital Damascus, another activist said tanks were still in the streets on Tuesday morning. - Reuters