Updated

Three inmates stabbed a prison guard to death in Maryland's troubled House of Correction, the second killing of an on-duty corrections officer in the state this year, officials said Wednesday.

The guard was on late night rounds in the maximum-security prison when he was attacked and stabbed several times in the neck and back, said Maj. Priscilla Doggett, a spokeswoman for the Maryland Division of Correction.

The officer's name was not released, pending notification of his family.

The prison was in lockdown Wednesday, and security teams from other prisons were sent to assist with a search of the entire facility, Doggett said. She said the three inmates accused in the attack had been taken a secure location.

The Maryland House of Correction has been wracked by violence and three inmates have been killed there since May. This week, a new warden was named in an effort to restore safety inside the 1,100-bed prison.

In late January, another Maryland corrections officer, Jeffery A. Wroten, 44, died after he was shot in the face with his own gun, allegedly by an inmate he was guarding at a Hagerstown hospital.