New Delhi (CNN)An Indian Air Force helicopter crashed Wednesday in the southern state of Tamil Nadu with Chief of Defense Staff, Gen.

Bipin Rawat on board, according to the Indian Air Force (IAF).The cause of the crash and details of other passengers are not yet known.

The IAF said “an Inquiry has been ordered to ascertain the cause of the accident”.

Three people have been rescued so far and moved to a hospital, according to public broadcaster Doordarshan.

This is a developing story … more to come

-CNN