Police launched a major assault Tuesday on a maximum-security jail taken over by al-Qaida linked suspects, killing at least 16 inmates in a raid that began with a barrage of tear-gas canisters and bullets.

Interior Secretary Angelo Reyes said the dead included four leaders of the Muslim extremist Abu Sayyaf group, including the two men who headed a botched escape attempt Monday that left another five people dead.

"We have taken control of all the floors," Metro Manila Police Chief Avelino Razon quoted the ground commander as saying less than an hour after the operation began.

Sporadic gunfire could still be heard, however, as police said they were conducting mop-up operations. At least five police officers involved in the assault were wounded.

The assault came shortly after Reyes said authorities were giving the inmates 15 minutes to surrender. That ultimatum came after hours of fruitless negotiations with the inmates.

As the deadline passed, police fired tear gas and officers and sharpshooters were seen running in and out of the main steel gates wearing gas masks.

Some detainees were seen scaling down the walls inside the compound as thick smoke billowed out. A police helicopter hovered above and ambulances waited for casualties.

The inmates had agreed to surrender after their failed jailbreak Monday, but the deal broke down when they demanded food first, prompting civilian negotiators to leave in frustration.

"There were so many people, they were hiding in their cells," said Napoleon Cabrera, a police officer who led one of the assault teams.

"Some were firing pistols, some were yelling because of the tear gas smoke," Cabrera said, adding that he got in a firefight with one rebel.

"I was hit in the leg. But I know he fell down," Cabrera said.

(Chinadaily.com via agencies March 15, 2005)