"The investigators evaluated the depositions of the surviving crew members and established that there were no (Philippine) military units in the area when that incident happened," AFP spokesman Col. Tristan Kison told reporters yesterday.
"It seems like its the doing of pirates," he added, noting that the AFPs investigation failed to establish the nationalities of the attackers.
The AFP investigators were led by Western Command chief Rear Admiral Tirso Danga.
Beijing had demanded an investigation after a Hainan-based vessel was boarded by unknown gunmen on April 26, killing four Chinese fishermen and wounding three others.
The attack took place in an area of the South China Sea that is claimed by both countries along with Brunei, Malaysia, Taiwan and Vietnam.
The 13 attackers stole the Chinese boats navigational and electronic equipment.
Last week, Chinas Southern Daily newspaper reported that Philippine ships could be behind the attack on the Jinghai 03012 since the attack vessel looked like one from the Philippines.
According to the report, Chinese fishermen who survived the attack claimed that several men in camouflage uniforms while the others in civilian clothes boarded their vessel.
This prompted Malacañang to direct the military to investigate the attack.
Taking exception to allegations that government troops were behind the attack on the Chinese fishermen, the AFP said the Philippines is not the only country that has an interest in the Spratlys.
The AFP said ships from other countries laying claim to the Spratlys could have been in the area when the Chinese fishing vessel was attacked.
The Spratly island group consists of more than 100 islets, atolls and reefs claimed in part or in whole by the Philippines, China, Taiwan, Vietnam Malaysia and Brunei.
Except for Brunei, all claimant countries have established their respective military garrisons in the area, considered as rich in mineral and oil deposits. With AFP