MANILA, Philippines — Communist guerrillas, disguised as anti-narcotics agents, barged into a poorly guarded provincial prison southeast of Manila and freed seven of their comrades in a daring 15-minute attack staged without firing a shot, officials said Sunday.

The 30 New People's Army guerrillas, most armed with machine guns, talked their way into the prison in Quezon province late Saturday, saying they were there to take custody of some of the inmates, and then overwhelmed the guards on duty.

The rebels then fled in four vans with the freed prisoners. They later clashed with police at a checkpoint, wounding two policemen and two civilians, Quezon police Chief Fidel Posadas said.

The rebels, some of whom were believed wounded in the gunbattle at the checkpoint, escaped toward a forested mountain and were being pursued by soldiers and policemen backed by air force helicopter gunships, Posadas said.

About half of the prison's 50 guards and the deputy warden were in Manila for a seminar, considerably weakening the provincial jail's defenses at the time of the attack, Posadas said. The warden and his deputy have been fired by local officials for the security lapses, Posadas said.

"The guards would not have been overwhelmed if they did not open the gates just like that when the disguised rebels appeared to seek custody of some inmates," Posadas told The Associated Press by telephone.

The rebels seized four pistols from the guards during the prison break-in. The four vans they used were found abandoned in Lucena city in Quezon, about 70 miles southeast of Manila, he said.

In a separate attack, an undetermined number of guerrillas opened fire Saturday on an army outpost near a sprawling banana plantation in southern North Cotabato province's Makilala township, sparking a clash that killed a pro-government militiaman, Makilala police Chief Ramil Hojilla said.

A soldier and two militiamen were wounded in the clash, Hojilla said by telephone.

The 5,000-strong Maoist rebels have been waging a communist rebellion in the country's rural regions for nearly 40 years. They have escalated their attacks against government forces in recent months to gain badly needed weapons, according to the military.

Norway-brokered peace talks stalled in 2004 after the rebels accused the government of instigating their inclusion in U.S. and European terrorist blacklists.