“All base personnel implement LOCKDOWN procedures and immediately take cover,” the base posted on Facebook and Twitter.
A second post said there were no immediate reports of injuries after the incident that took place outside one of the gates.
“(Base) emergency responders are working with the San Antonio police department to clear the area and search for the shooters,” the post says.
Joint Base San Antonio comprises three locations, including Lackland, located in western San Antonio. The base is the largest joint base of the Department of Defense, according to the base website.
This is a developing story and will be updated.