Published: Nov 18, 2010 7:25 PM EST
Updated: Nov 18, 2010 4:05 PM EST

TAMPA, Fla. (AP) - Officials are searching the wreckage of a small, civilian plane that crashed while assisting with a military training exercise in rural central Florida. No military officials or weapons were onboard.

The National Transportation Safety Board confirmed there are fatalities, but did not say how many. It's unclear how many were onboard the flight that crashed Wednesday night in Avon Park.

 U.S. Special Operations Command spokesman Maj. Wes Ticer did not offer details on what the plane was doing during the exercise, but says it's not uncommon for authorities to use civilian planes for training when military planes aren't available.

NTSB spokesman Terry Williams said the agency is investigating.