Residents of Hama said security police and state militiamen, known as shabbiha, raided houses overnight in the al-Sabouniya and al-Marabet districts, after troops backed by tanks arrested dozens in two other neighborhoods of the city the night before.

"The inhabitants are responding by shouting 'God is greatest' from windows and rooftops. Tonight there are more random raids as opposed to what the army did yesterday, which was go into specific houses looking for suspected activists on a list," Haidar, a local activist, told Reuters by phone.

Five months of protests have failed to unseat President Bashar al-Assad, who inherited power from his father and retains the loyalty of the core of his armed forces comprised mostly of members of the Alawite minority, the same sect as the president.

But demonstrators have been encouraged by the fall of Libya's Muammar Gaddafi and rising international pressure on Syria, including a planned European Union embargo on the oil industry which would disrupt a vital source of income.

Reuters