The soldiers, belonging to the Armys 75th Infantry Battalion, were returning to base after fetching water when one of them tripped on a land mine buried by the roadside in Sitio Kupah, Barangay Lanao Dakula.
Two soldiers died on the spot, while two others were wounded. Military ordnance experts later found and defused 10 more mines in the area.
The military refused to identify the slain soldiers pending notification of their families. Wounded were Sergeants Leonardo Hilare and Adonis Canobida.
"We believe that these land mines were planted by the Abu Sayyaf," said Brig. Gen. Alexander Aleo, chief of the Joint Task Force Comet which has been going after the Abu Sayyaf in Sulu.
Last April 24, three men of the 51st Infantry Battalion were killed and 11 others were wounded in a land mine explosion following an attack by the Abu Sayyaf, also in Sulu.
Aleo believes that the Abu Sayyaf unit led by Tahil Sali, a land mine expert, was behind the incidents.
Sulu is a stronghold of Muslim armed groups, including the Abu Sayyaf, a small group of militants linked by the Philippines and the United States to Osama bin Ladens al-Qaeda terrorist network.
The group is wanted for a spate of kidnappings in the South in recent years and is behind the countrys worst terrorist attacks. Roel Pareño, Jaime Laude and AFP