COTABATO CITY — The 2nd Marine Battalion Landing Team revealed on Monday that a security alert has been raised in the Lanao del Sur coastal town of Picong following an ambush that injured three Marine troopers.

MBLT-2 commander Lt. Colonel Serge Ronquillo said that a team of soldiers on board a military vehicle was patrolling in its area of operation when ambushed at about 6 p.m. Sunday.

"A pursuit operation is going on," Ronquillo said.

He identified the injured soldiers as Privates First Class Stephen Saragal, Elijah Taccas, and Private Romy Torallo Jr., all of MBLT-2.

All three sustained limb injuries.

Ronquillo stressed that they are trying to determine the armed group behind the attack.

Additional Marine checkpoints have been set up along strategic sections of Picong following the attack.