(CNN) -- An access point to Fort Hood in Texas was briefly shut down Wednesday after guards discovered a live grenade during a random vehicle search, officials said.
At about 9:15 a.m., guards alerted Fort Hood Emergency Services after finding the live munition and closed Clarke Gate for about 30 minutes, according to a Fort Hood news release.
Security at the Army post remains heightened following a mass shooting on November 5 that left 13 people dead. Army psychiatrist Maj. Nidal Malik Hasan is charged with 13 counts of pre-meditated murder and 32 counts of attempted murder in the shootings. He is currently awaiting trial.
The single grenade, which is made for a Mark 19 40mm grenade launcher, was found inside a serviceman's car, Fort Hood spokesman Tyler Broadway told CNN.
There is an investigation under way to determine what, if anything should happen to the serviceman, Broadway said.
CNN's Larry Shaughnessy contributed to this report.