MANILA, Philippines -- Two Army soldiers are being investigated amid allegations the looting of their armory in Compostela Valley over the weekend was an inside job, a spokesman for the Philippine Army said Monday.

Several other soldiers from the 534th Engineer Combat Battalion have been restricted to their headquarters at Camp Kalaw in Monkayo town while the investigation is ongoing, Lieutenant Colonel Romeo Brawner Jr. said.

Twenty high-powered firearms, including 15 M16 rifles, two M14 rifles, an M653 assault rifle, an M60 light machine gun, and an M203 grenade launcher were taken from the battalion’s armory.

"The execution was very well-planned. It could be an inside job and not a raid, contrary to what was written in the news," Brawner said in a statement, quoting the commander of the 52nd Engineer Brigade, Colonel Romulo Cabantac.

In fact, Brawner said, "Right from the start, they suspected that it was an inside job."

The possible inside job was uncovered in separate investigations by the 534th Engineer Combat Battalion commander, Lieutenant Colonel Alfredo Soriano, and police scene of the crime operatives (SOCO), Brawner said.

The looting was believed to have happened amid a heavy downpour on Saturday morning.

Brawner said the suspicion was that the missing weapons were passed over the camp’s perimeter fence.

The unit's company assistant supply sergeant discovered that the firearms were missing, the spokesman said.