A guard at the Fulton County Jail is stable in an Atlanta hospital after being stabbed by an inmate Thursday morning.

Another inmate had to step in to help the detention officer, who was not identified, according to a statement from Fulton Sheriff Patrick Labat.

The sheriff told Channel 2 Action News an inmate grabbed the officer from behind and stabbed him in the back of the head with a homemade shank. The officer sustained defensive wounds to both shins, the news station reported.

He was taken to Grady Memorial Hospital.

The sheriff’s office is investigating the stabbing. Labat said the attacker, whose name was not released, will face additional charges.

“The safety and security of staff, inmates and visitors at the Fulton County Jail is our top priority,” he said in the statement. “The jail is secure and the investigation is active and ongoing.”

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