BANGKOK, July 18 (Xinhua) -- A civilian helicopter crashlanded, killing four people on board in northeastern Thailand on Wednesday.

An Eurocopter AS355 light utility helicopter crashlanded in Chonnabot district of Khon Kaen province, about 450 km northeast of Bangkok, at local time between 9:00 a.m. and 9:30 a.m., killing the three unidentified people aboard, according to Atthaya Lapmak, director of Khon Kaen airport.

The white-painted helicopter was engulfed by a blaze immediately after it had crashlanded in a rice farm, the airport official said.

Poor visibility and heavy rains were believed to have caused the fatal crashlanding of the helicopter which had taken off from the neighboring Saraburi province with Khon Kaen airport as its destination, he said.

Authorities have launched investigation into the incident.