BANGKOK, July 5 (Xinhua) -- A surveillance plane of the Thai army crashlanded in Thailand-Myanmar border area on Thursday, an army officer said.

It remains unknown whether four army officers, including two pilots, on board the army's Cessna U-17 light aircraft may have survived the crashlanding.

The accident took place in the Thailand-Myanmar border area of Pang Mapha district of Mae Hong Son province, about 890 km north of Bangkok, according to the army officer attached to the northern-based Third Army Region.

Troops of a task force of the 17th Infantry Regiment scrambled to get to the mountainous area where the aircraft was believed to have crashlanded, he said.

The turboprop-engine plane has gone missing from the radar screen at about 11:00 a.m. local time Thursday.