An Air India Express flight from Dubai slipped away from the runway and fell into the valley at Calicut International airport in Karipur near here, late on Friday night.
The Malappuram SP Abdul Kareem said there could be casualties but no count was possible since rescue operations are progressing.
A table top airport, the slipping off from the runway in the rough weather condition is considered something similar to that occurred in Banjpe airport in Mangalore few years ago.
As many as 191 persons, including crew, were on board. The flight is reported to have split into two parts and there is no clear idea about the casualties, sources said.