An inmate assaulted a corrections officer in a central Minnesota jail while a lockdown was being implemented, authorities said.

Joshua D. Peterson, 26, serving time from an earlier conviction for assault with a dangerous weapon, punched the Stearns County officer in the face Thursday, according to Sheriff Steve Soyka.

Several officers subdued the uncooperative inmate, who now awaits charges on the jailhouse assault, the sheriff said.

The officer was treated for his injury and released from the hospital, Soyka said.

A more serious assault on a corrections officer occurred a few days earlier in neighboring Sherburne County.

Hakeem A. Coles, 24, was on a telephone last Monday along a second-floor jailhouse walkway when he ambushed the officer from behind with a blow to the head, Sheriff Joel Brott said.

The 50-year-old officer fell to the floor, and Coles hit him again in the head "multiple times," Brott said in a statement. Other officers intervened and detained Coles without further violence.

The officer was taken to a hospital with "serious injuries [but] is expected to make a full recovery," said the sheriff.