Suspected Abu Sayyaf guerrillas are believed responsible for the mine which blew up the troops vehicle while they were en route to Maimbung town to deliver supplies.
One soldier was instantly killed and an army lieutenant died later, said military spokesman Lt. Col. Buenaventura Pascual.
Reports reaching Camp Aguinaldo identified the fatalities as Lt. Fabia, and a certain Pfc. Bauron, both of Alpha Company, 53rd Infantry Battalion, whose commander, Lt. Col. Dennis Villanueva, was also killed in a mortar attack by Abu Sayyaf bandits last February.
Fabia died while undergoing treatment at a military hospital in Jolo, while Bauron was killed on the spot, the report said.
Pascual said the five wounded soldiers were airlifted to the 104th Infantry Brigade in Jolo for treatment.
He added that the soldiers were delivering supplies to their colleagues in the front lines when their vehicle hit the landmine planted by the bandits in the vicinity of Mt. Karao, Maimbung.
Immediately after the explosion, the bandits who were hiding behind the bushes, fired at the soldiers, who held their ground while waiting for reinforcements.
It wasnt clear how many soldiers were in the vehicle but Pascual said the Army reinforcement were able to inflict heavy casualties on the bandits.
Yesterdays attack confirmed military intelligence reports that the bandits are planning a major offensive against government troops in Sulu.
The attack, which took place three days after the visit of US Ambassador Francis Ricciardone to Jolo, also coincided with the ongoing civic and humanitarian missions spearheaded by the United States in the island province. With AP, AFP