MANILA, Philippines -- Three soldiers were killed and another was wounded after they clashed with alleged communist guerillas in the northern province of Kalinga, an Army official said Friday.

The encounter started around 4 p.m., when troops from the 21st Infantry Battalion encountered an estimated 40 New People's Army (NPA) rebels in Ab-abaan village, Balbalan town, said Lieutenant Colonel Antonio Lastimado, the battalion commander.

The same group of rebels was allegedly behind an attack on a Globe Telecom Inc. cell site in Pinukpuk town, Kalinga last week, Lastimado said in a phone interview.

Lastimado said the rebels suffered an undetermined number of casualties based on traces of blood on the scene of the encounter.

President Gloria Macapagal-Arroyo has given security forces until the end of her term in 2010 to defeat the NPA, the 5,000-strong armed wing of the Communist Party of the Philippines (CPP).