New People’s Army rebels ambushed a platoon of soldiers patrolling in a remote village in the island of Mindoro just south of Luzon Saturday morning killing 11 soldiers and wounding seven others.

It was the worst government loss this year coming just three weeks before the communist-led rebel forces celebrate their 41st founding anniversary.

Reports said the government troops were responding to reports of the presence of armed men in the village of Panaytayan town in Oriental Mindoro when they were ambushed by an undetermined number of NPA guerillas.

Lt. Col. Romeo Brawner Jr. of the Armed Forces Philippines’ public information office said soldiers led by 2nd Lt. Ronnie Sipsip engaged the rebels in a three-hour encounter but were placed in a disadvantaged position.

Government forces are conducting “clearing operations” in preparation for the May 10 elections to neutralize the NPAs who were reported to have been demanding fees from candidates to be able to campaign in “rebel-held territories.”

There were no immediate reports of casualties from the rebel side.

The NPA, the armed wing of the Communist Party of the Philippines (CPP), has been waging a Maoist-inspired guerilla war in the countryside. It was founded on March 29, 1969. The NPA claimed it has grown from a ragtag band to a nationwide “people’s army” operating in at least 120 guerilla fronts all over the Philippines.

Government security officials, however, said the number of NPA rebels had gone down to less than 5,000 armed regulars from a high of 25,000 during the peak of rebel activities in the mid-80s.

More than 40,000 have already been killed in more than four decades of guerilla activities in the country.