At least one active shooter and security forces at Joint Base San Antonio (JBSA) exchanged fire early this morning around 4:30am. JBSA officials announced that the incident took place early on Saturday, according to Fox News. 

Security forces returned fire on at least one drive-by suspect, according to the outlet. There were no injuries immediately reported. JBSA said in a press release that they do not think that the shooters were military. The shooting was not a threat to the base from initial reports.

A Facebook post from JBSA officials announced after the incident, “The main gate at JBSA Chapman Training Annex has been closed until further notice. Please use alternate gate located North of primary on Ray Ellison Boulevard.” JBSA-Chapman Training Annex reopened around 9:30am local time. 

"There was no active threat to the installation … and our security forces responded to mitigate the threat," spokesperson Stefanie Antosh said of the situation. Antosh noted that the suspects did not try to breach the gate.

Police arrived on the scene to assist in the investigation after the shooting took place. It was not initially clear how many shooters there were and what the motivation was to fire upon the base. 

The incident took place at the Chapman Annex, which is west of Lackland's main facilities, is home for Air Force special warfare training, according to San Antonio Express News. The base has resumed normal operations.  

This is a developing story. Please refresh for updates.