Six inmates — including two who are charged with murder — escaped during the night by overpowering a guard at the understaffed county jail, authorities said. Two were captured Sunday.

The men escaped late Saturday from a special unit at Cook County Jail for inmates with disciplinary problems. One guard was on duty instead of two because of staffing shortages, said county Sheriff's Department spokesman Bill Cunningham.

One inmate threw hot water from a shower on the guard and held him at bay with a homemade knife, then handcuffed the guard and put on his uniform, officials said.

That inmate was caught after opening doors to let the other six inmates out. They got over a barbed wire fence and onto the streets.

The inmates who were captured Sunday were identified as Arnold Joyner, 43, charged with theft and battery; and David Earnest, 38, charged with murder.

They were caught about 7 miles from the jail in Oak Park.

The four at large Sunday were Franciso Romero, 23, charged with murder; Eric Bernard, 22, charged with armed robbery; Michael McIntosh, 30, charged with aggravated battery with a firearm; and Tyrone Everhart, 28, charged with aggravated kidnapping.

It was the second jail break since Friday. An inmate facing armed robbery charges broke out Friday by apparently slipping into a laundry truck, but he was arrested Saturday at a suburban motel, authorities said.