MANILA (AFP) - Convicts in the Philippines's main prison turned over an arsenal of firearms and improvised weapons including an Uzi machine-gun as part of a crackdown on privileged jail birds, the Justice Department said Monday.

Despite the haul, Justice Secretary Leila de Lima fired four jail officials and said she suspected prison gangs were still holding on to weapons and narcotics even after a deadline for the surrender of contraband items passed.

De Lima has been trying to clean up the prison system after two surprise searches of the Bilibid prison earlier this month uncovered a horde of prohibited items including firearms, drugs, stashes of US dollars - and even a jacuzzi and a stripper bar.

"I'm very disappointed because I have a gut feel that the gangs still have in their possession several weapons and illegal drugs and that what they surrendered are the weapons that they can no longer use," de Lima told reporters after receiving eight boxes of surrendered items.

She had earlier given the convicts in Bilibid until Christmas Eve to surrender banned items and had set up boxes in the jail where these objects could be dropped in. That deadline was later extended to Monday.

Seven commercial firearms, including an Uzi, were turned in along with 14 improvised shotguns, over 260 bladed weapons and 341 mobile phones as well as mobile phone and computer accessories, according to a list provided by the Justice Department.

The convicts also turned over improvised drug paraphernalia but did not turn over any prohibited drugs, a sign they were still hiding them, de Lima said.

De Lima did not say what further action would be taken but has previously said she would continue to press on with the crackdown.

Revelations that drug lords have been "living like kings" in luxury cells shocked the Philippines, a nation used to tales of official corruption.

President Benigno Aquino has ordered de Lima to reform the prison system, which has long been known for corruption, with wealthy inmates enjoying special privileges.

She earlier fired three officials connected with Bilibid ahead of an investigation over the apparent complicity of jail officials in allowing the items to be smuggled in.