An airman killed his commander before apparently turning the gun on himself, sparking a lockdown at Joint Base San Antonio-Lackland in Texas Friday, a U.S. official confirmed to Fox News.

The shooting was not an act of terrorism, an FBI investigator said. 

The two men were found dead in an office in Forbes Hall on the base's Medina Annex, Air Force Brig. Gen. Robert D. LaBrutta reported. He added that teams found two handguns at the scene, but did not say whether both belonged to the shooter.

Investigators did not identify either of the dead. Police cleared other nearby buildings, Fox 29 adds.

Joint Base San Antonio-Lackland is approximately 10 miles southwest of San Antonio. It's home to a U.S. Air Force boot camp. Officials also locked down nearby schools as police investigated.

The initial reports of the shooting came in at 8:30 a.m. local time, Bexar County sheriff's spokeswoman Rosanne Hughes told Fox News.

Later Friday, officials were investigating whether the the gunman was authorized to have a weapon on the base.

The deadly shooting is the latest to occur at a military facility in Texas in the last several years.

In January 2015, an Army veteran and former clerk at the veterans' clinic at Fort Bliss in El Paso shot and killed a psychologist, then killed himself. About a year earlier, three soldiers were killed and 16 wounded in an attack at Fort Hood near Killeen by Army Spc. Ivan A. Lopez, who also killed himself.

And in the deadliest attack to occur at a U.S. military installation, 13 people were killed and 31 were wounded in a mass shooting in 2009 at Fort Hood. Nidal Hasan, a former U.S. Army major, was convicted and sentenced to death in that shooting.

The Army's Fort Sam Houston and Air Force's Lackland and Randolph bases were combined during base realignment several years ago to become the military's largest joint base.

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Fox News' Casey Stegall, Lucas Tomlinson and The Associated Press contributed to this report.