At least two policemen were wounded in an ongoing encounter with suspected members of New People\'s Army (NPA) in southern Philippines, police said Friday evening. Philippine National Police spokesman Chief Superintendent Agrimero Cruz Jr. said the clash started at around 6 p.m. in Anomar Upper Sangay village, Sison town, Surigao del Norte province. As a result, two police personnel were slightly wounded while the NPA rebel side sustained undetermined number of casualties, Cruz said, adding firefight was still ongoing as more police and military troops came to reinforce the law enforcers. The NPA, armed wing of the Communist Party of the Philippines, has been waging a guerrilla campaign in the countryside for more than four decades. The Philippine military estimates more than 4, 000 NPA guerrilla fighters are scattered in over 60 provinces throughout the Southeast Asian country.