A T-6 Texan II training aircraft from Sheppard Air Force Base in Texas crashed Wednesday afternoon, the base said. The pilot and co-pilot are believed to have safely ejected from the plane.

Sheppard said in a tweet that the T-6 crashed a little before 2 p.m. local time near Lake Waurika, southwest of Hastings, Oklahoma.

In an update posted on Twitter Wednesday evening, Sheppard said that both pilots have returned to base. They were conducting a pilot instructor training mission at the time of the accident, Sheppard said.

An investigation is under way, the base said, and emergency crews are on the scene. Sheppard asked anyone who finds debris to not touch or move it, and instead to call the base at 940-676-2616.

This is a breaking news story. It will be updated as events unfold.