NAIROBI, Kenya — Kenya police say they have launched a search and rescue operation for three Swiss nationals after the airplane they were in went off radar in central Kenya on Thursday.

A county police commander, Naomi Ichama, said Friday the Cessna 206 was headed to Wilson Airport in Nairobi from Nanyuki in central Kenya when it went missing at about 5 p.m. Thursday.

Ichama says authorities are investigating reports that the plane developed mechanical problems before it went off radar.

Ichama said police officers and wildlife service officials, with the help of three helicopters, were searching for the plane in the Aberdares mountain range in central Kenya.