Three Philippine government soldiers were killed and six others were wounded in an ambush by terrorist Abu Sayyaf group in southern Philippine province of Sulu on Wednesday, the military said.

The soldiers were hit by a landmine when they were on their way to conduct resupply and road security at Patikul town in Sulu around Wednesday noon, said the Armed Forces of the Philippines ( AFP) spokesman Restituto Padilla.

"Two of the slain soldiers were young officers," Padilla said.

A two-hour firefight ensued against the undetermined number of perpetrators with no immediate reports of casualties on the enemy side, he added.

"We have had successes (against the Abu Sayyaf), but we have had also losses," he said.

The attack came on the same day Armed Forces chief Gregorio Pio Catapang visited government forces in Jolo town, also in Sulu.

AFP public affairs office chief Harold Cabunoc, who accompanied Catapang in the visit, said the AFP went to Jolo "to boost the morale of soldiers." He said Catapang awarded medals during the visit for past accomplishments.

The 400-strong Abu Sayyaf Group (ASG) is notorious for a series of kidnappings, bombings and even beheadings in southern Philippines over the past decades. The ASG operates mainly in Basilan, Sulu, and Tawi-Tawi Provinces in the Sulu Archipelago and has a presence on Mindanao.