— MONTGOMERY, Ala. (AP) — Three University of Alabama football players have been charged with knocking students unconscious and stealing their wallets, while a fourth player has been charged with using a stolen debit card, officials said Tuesday.

Linebacker Tyler Hayes, 18, and safety Eddie Williams, 20, confessed to robbing a student who was punched in the head and face and kicked in the ribs and back early Monday morning, according to court documents. Williams said D.J. Pettway, 20, a defensive lineman, and Hayes waited in a nearby vehicle about an hour later while he knocked out and robbed another student. Williams and Hayes both admitted to their involvement, according to the documents.

Williams and running back Brent Calloway, 20, both admitted to using a stolen credit card to buy snacks from vending machines inside a dormitory, the documents said.

All four students were indefinitely suspended by coach Nick Saban.

Pettway and Hayes were charged with second-degree robbery. Williams was charged with fraudulent use of a credit card and second-degree robbery. Calloway was charged with fraudulent use of a credit card. Williams was released on $65,000 bond, while Hayes and Pettway were released on $60,000 bond each. Calloway was released on $5,000 bond.

"This behavior is unacceptable for any student-athlete at the University of Alabama and not representative of our football program," Saban said in a news release.

All four players were backups last season for Alabama, which has won two straight national titles and three of the past four. Williams didn't play in 2012. But he was one of the nation's top prospects the previous year and moved from receiver to safety.

The first student reported having his Apple Macbook Pro stolen from his backpack. Both sustained mild concussions, cuts on the face and heavy swelling, and had their wallets taken, according to documents.

University police posted an advisory Monday saying two students reported being approached by two men who asked for a light for a cigarette.

Police also said Williams had been arrested on a charge of carrying a pistol without a permit a day before his arrest on the robbery charges. Tuscaloosa police Sgt. Brent Blankley said in a news release that a clerk at a gas station called police early Sunday, telling officers that Williams threatened that he had something in his trunk after a fight about paying for gas.

Officers who pulled over Williams found a pistol in his pants pocket, the release said. In that case, he was released on $500 bond.

Jail records did not show whether any of the players had an attorney.

Pettway, who was a redshirt freshman, played in 13 games and had 2 1/2 sacks and eight tackles.

Hayes had 14 tackles as a freshman.

Calloway played mostly on special teams but gained 63 yards on 10 carries. He has moved around on the field, working as a linebacker, tight end and H-back since Alabama signed the onetime Auburn commitment.

Calloway was arrested on a charge of marijuana possession in October 2011 during a redshirt season.