According to media reports, several people died in the crash, which is said to have happened around 10:20 a.m. (0820 GMT) in a steep and forested area in the Neuchatel Mountains.
Police said they would hold off on providing information on the plane that crashed, how many people who had been onboard and how many who may have perished or been injured until their families had been informed of the accident.
Rescue services and police are at the scene of the wreckage, and authorities have opened an investigation into the circumstances surrounding the crash, the RTN broadcaster reported.