SAN ANTONIO (AP) — An Air Force base in San Antonio went on lockdown Wednesday afternoon for an “active shooter warning,” but there were no immediate reports of injuries.

Joint Base San Antonio issued the alert midday, telling all Lackland Air Force Base personnel to go into lockdown. An alert on Twitter said: “Real World, LOCKDOWN, LOCKDOWN, LOCKDOWN.”

A spokeswoman for JBSA said she could not immediately provide any information but that officials were preparing a statement.

San Antonio police said they were “assisting” in the situation but referred questions to the base.

The Associated Press