BEIRUT (AFP) - Syrian regime forces stormed a prison in central Homs province overnight to put down a riot by inmates, injuring several, the Syrian Observatory for Human Rights said on Monday.

"Several people were injured and there are reports that people were also killed when regime forces stormed Homs central prison," Observatory director Rami Abdel Rahman said.

Homs-based activist Yazan said the clashes came when prisoners rioted after authorities tried to move them.

Syrian authorities have reportedly been transferring prisoners to facilities inside airports and military barracks that could be targeted in any US-led strikes.

"Security forces fired bullets and tear gas and used tasers against the prisoners," he said.

He said water and electricity to the prison had been cut, but said there was no indication that prisoners had been killed in the incident.

The Syrian opposition National Coalition issued a statement on the incident saying it had been informed of a "crackdown and use of live bullets to put down an attempted uprising at the prison".

Elsewhere, in northern Homs province, the Observatory said at least 11 policemen were killed and at least 10 others injured in a rebel rocket attack against their headquarters overnight.

"Eleven policemen were killed and 10 others were injured, including some in critical condition, after three rockets were fired against their position," the Observatory said.

The group also said additional rocket attacks launched from rebel positions targeted several neighbourhoods of the city of Homs that are mostly inhabited by Alawites, the Shiite offshoot from which President Bashar al-Assad hails, overnight.