MINOT (AP) - Two Ward County Jail correctional officers suffered head injuries after they were assaulted by an inmate trying to escape, authorities said.

Ward County Sheriff Vern Erck said Mike Ihla was unconscious for a time and underwent a CAT scan on Saturday following the attack. Officer Wyat Klabunde had a less serious head injury but was taken to a hospital for observation, he said.

Both men were released from the hospital late Saturday, Erck said.

The officers were escorting a group of 20 inmates to the third floor of the jail for recreational activities, Erck said.

Cornelious Allen, 22, who was not cuffed or shackled, pushed Ihla and knocked him to the floor, Erck said. Ihla hit his head on the floor and was knocked unconscious, the sheriff said.

Another inmate alerted the Klabunde, who went to assist the injured officer, but Allen "blindsided" Klabunde, knocked him to the floor, and kicked and punched him, Erck said.

Erck said the other 19 inmates did nothing to stop the assault.

"They just stood and watched," said Erck.

Authorities had been warned that Allen had been talking about making an escape to avoid a court appearance, Erck said.

Allen was shackled when he made his last court appearance. He was arrested and charged with nine counts of burglary, one count of attempted burglary. He also has three bench warrants in Colorado.

Allen will likely face additional charges of felony assault and attempting escape, Erck said.

Ward County prosecutors will consider the additional charges on Monday, Erck said.

Allen is still being held at the Ward County Jail, Erck said.