MANILA, Dec. 29 (Xinhua) -- The Philippine military is ready to extend assistance in search for the missing AirAsia plane, a senior officer said on Monday.

Armed Forces of the Philippines chief of staff General Gregorio Pio Catapang Jr. alerted military units conducting maritime patrols over Philippine territorial waters to be extra observant and report any unusual sightings that may provide possible leads in locating missing AirAsia flight QZ8501.

Catapang also placed these units on on-call status and directed them to stand ready to provide assistance when needed.

Specifically, Catapang said, the Philippine Navy and Air Force have been alerted and are placing on standby two C-130s, two Fokker planes, one Islander and the Navy vessel PF-16.

An Airbus A320-200 of the Malaysia-based AirAsia vanished from the radar screen Sunday morning soon after it took off from Surabaya in Indonesia's East Java province.

The Singapore-bound plane carried 155 passengers and seven crew members, including 16 children and an infant. Most people on board were Indonesians, and foreign nationals were from Singapore, Malaysia, South Korea, France and Britain.