Communist rebels in the Philippines killed five policemen and wounded six others Thursday in an ambush, according to police and military officials. Authorities suspect the New People's Army rebels are behind the attack.

Lieutenant Colonel Roderick Parayno, a regional military spokesman, said the rebels detonated an improvised landmine while the policemen were on their way to Batasan village in San Jose town in Occidental Mindoro province, some 255 km south of Manila, to provide security to a candidate running for governor in elections next week when they were attacked.

"A landmine explosion preceded the volley of fire from the communist rebels, numbering about 30," Superintendent Nestor Rosero, a regional police spokesman, said.

Rosero said five policemen were killed on the spot. Some 30 suspected members of the New People's Army opened fire at the policemen. According to the police, only three policemen were unharmed. Parayno said a joint team of army troops and policemen have been dispatched to hunt down the guerrillas.

"Soldiers were sent to help the local police chase the rebels and provide extra security to candidates due to the campaign in the area," Parayno said. “The security forces have began pursuit operations, but there is no contact so far," he added.

"We received information the withdrawing rebels were carrying two improvised stretchers to evacuate their casualties."

According to the government's recent estimate, the New People's Army rebels allegedly have 7,000 strong members throughout the country. Communist rebels have been fighting the Philippine government since the late 1960s, making the movement one of the longest-running leftist insurgencies in Asia.