MANILA, April 3 (Xinhua) -- At least 31 Philippine soldiers, including two military officers, have been wounded in fresh clash with Muslim militants in the southern Philippine Sulu province, the military said Monday.

Col. Cirilito Sobejana of the Philippine Army said that a lieutenant colonel and a lieutenant were among those hit by shrapnel from explosives fired by more than 100 Abu Sayyaf militants during a heavy fighting that broke out Sunday in a remote town in Sulu province.

He said the firefight lasted about half an hour, adding that the bandits were forced to flee from pursuing troops.

Sobejana said the two officers and the rest of the injured soldiers are now in stable condition and recuperating in local hospitals.

"Most of the wounded soldiers were hit by the grenade," he said, claiming that majority of those injured sustained only "minor injuries".

Philippine Army was also able to find the body of one Abu Sayyaf who was killed during the firefight. His identity is yet to be known.

Abu Sayyaf is one of the smallest and most violent jihadist groups operating in the southern Philippines notorious for kidnappings, bombings and attacking civilians and the army.

The group, numbering about 500, has been sowing terror in the southern Philippine region since the early 1990s.

Philippine President Rodrigo Duterte has ordered the military to launch an all-out offensive against the Abu Sayyaf bandits operating mostly in the hinterlands of southern Philippine provinces of Sulu and Basilan.