Two people were killed in an apparent murder-suicide at Lackland Air Force Base in San Antonio on Friday that triggered a lockdown at the facility, the Bexar County Sheriff's Office said.

"It's over," Bexar County Sheriff's office spokesman James Keith said, adding that deputies were still on the scene. The lockdown on the facility and nearby schools has been lifted, the office said.

The commanding officer of the 331st K-9 Training Squadron at the base was shot by an airman, according to the Air Force Times, an independent news outlet, citing internal Pentagon communications. Neither person was immediately identified by the news outlet.

The victims have not been identified by the sheriff's office.

The incident took place at the Medina annex at the facility, where dog training takes place.

Keith said the sheriff's office did not believe there were other victims but deputies were searching buildings "out of an abundance of caution."

The Federal Bureau of Investigation was called to assist and has taken the lead in the case, the sheriff's office said.

Lackland is a key training installation for the Air Force.