A correction officer was slashed by an inmate on Rikers Island Thursday, authorities said.

The officer was the victim of “an unprovoked assault with a weapon” at about 4:30 p.m. inside the facility, according to a Department of Corrections spokesman.

The unconscious guard was taken to Elmhurst Hospital Center in Queens with non-life-threatening injuries, a source said.

The department spokesman said city Correction Commissioner Joe Ponte’s “top priority” is safety.

The DOC was seeking to arrest any inmate involved in the attack, he added.