Two of four airmen involved in an accident during a routine training mission Thursday morning were killed.

The accident involved two T-38 Talons, each carrying two airmen, at Vance Air Force Base in Garfield County, Oklahoma, the base said in a statement posted to its social media accounts. The "aircraft mishap," as the base called it, occurred around 9:10 a.m.

A security forces squadron at Vance Air Force Base in Okla., on Sept. 11, 2019. Airman 1st Class Cameron Schultz

"Vance emergency response personnel are on scene to treat casualties and assist in recovery efforts," the statement read. "A safety investigation team will investigate the incident."

The names of the airmen were not immediately released.

This is a developing story. Check back for updates.