A New York City correction officer is recovering after being stabbed roughly fifteen times in the head by an inmate, officials say.

The city's Department of Correction say the attack happened Monday afternoon at the Anna M. Kross Center on Rikers Island. It's unclear what led to the assault, but authorities say the officer was working in the protective custody unit when the incident happened.

The officer is currently undergoing tests, and the DOC says the attacker has been re-arrested.

Officials released a statement on the incident saying, "This was an unprovoked heinous and callous attack on one of our dedicated officers, who was simply doing their job. We will not tolerate any assaults on our members of service who show up to work each day to keep our jails safe."