Manila - Seven government troops were killed and 11 others wounded Sunday in an ambush by unidentified assailants in the southern Philippines, an army spokesman said.

The gunmen opened fire on a convoy of army soldiers and militiamen in the boundary of Mulondo and Baudiposo-Buntong towns in Lanao del Sur province, 810 kilometres south of Manila.

Lieutenant Colonel Romeo Brawner said the identities of the attackers were not immediately known, but Muslim separatist rebels are known to operate in the area.

Four army soldiers and three government militiamen were killed in the ambush, he said. Eight soldiers and three other militiamen were wounded in the attack.

The ambush came just days after fierce fighting ended between government forces and separatist Moro Islamic Liberation Front (MILF) rebels in the southern province of North Cotabato.

Nearly 160,000 people were displaced by the hostilities in North Cotabato, but more than half of them have already returned after government troops drove away MILF rebels from their villages.

The 11,000-strong MILF is the largest Muslim rebel group fighting for the establishment of an independent Islamic state in the southern region of Mindanao. (dpa)