SUNBURY - City police continue to investigate an assault last week at the Northumberland County Prison that caused minor injuries to three correctional officers.

Sunbury City Police Chief Stephen Mazzeo said the investigation is being conducted by Cpl. Jamie Quinn.

"We are waiting for the statements of the witnesses and victims," Mazzeo said Thursday. "After we have them, we will be going to the district attorney to discuss the charges."

Mazzeo said the inmate accused in the April 11 attack is back in state custody.

"He's not going anywhere," he said.

Northumberland County Commissioner Rick Shoch, acting chairman of the county prison board, did not identify the prisoner or the guards involved, but said the injuries were minor. Two guards were assaulted by the inmate and a third was injured in a scuffle while taking him into custody, Shoch said Thursday.

"All the injured received treatment and were back on duty within hours," he said.

The prison was placed on lockdown following the incident, and that restriction was lifted early Tuesday morning, Shoch said.

Shoch said the inmate was being housed in Northumberland County Prison from a state facility in order to attend a hearing in county court last Friday. He said no weapon was smuggled into the prison.

"He managed to break something off inside the prison and fashioned it into the weapon used in the assault," Shoch said. "That's all we can say about it at this point."

Prison officials asked the state Department of Corrections to do a sweep of the prison, but it could not be done over the weekend.

"We had some of our own people do a sweep, and I don't think that yielded any additional weapons," Shoch said.

Warden Roy Johnson and Commander Brian Wheary were not available for comment Thursday afternoon.

Shoch thanked the Sunbury City Police and Northumberland County Sheriff's Department for their prompt response and professionalism during this time.