Watch out. Naomi Campbell has been set loose.

The supermodel with the notorious anger management problem is out on bail after being arrested Thursday night (April 3) for allegedly assaulting a police officer at London's Heathrow airport.

Apparently, Heathrow's Terminal 5 for British Airways has had its share of luggage hassles ever since it opened its state-of-the-art facility last week, where more than 20,000 pieces of luggage have gotten mired there. Campbell's camp claims that a lost bag is at the root of Thursday's disturbance.

"Naomi was flying to Los Angeles for a memorial service on Thursday, April 3rd," says her rep in a statement. "She arrived at Heathrow Terminal 5 in plenty of time, checked her two bags in and was told they would make the flight. [On board,] she was told one bag could not be found and was missing. BA decided to resolve this by insisting she leave the flight and then called the police to forcibly eject her."

An unidentified airport source tells People a different story.

"She was really obnoxious when she arrived at the check-in and because of that, they didn't let her into the VIP lounge," says the source, adding that Campbell then tried to board with two large, hand-held bags. "She was asked to have the second bag checked in and that set her off. The aircrew had to call police. She threw a few things around the cabin and then spat at the cops."

An officer confirms the incident: "They tried to calm her but she lashed out at the cops, too. The last straw was spitting."

Campbell was released on bail shortly after midnight on Friday, April 4. She is due back at Heathrow within the next six weeks to see if she will face a trial.

The 37-year-old supermodel is famous for losing her temper and throwing her cell phone at her housekeeper. She pleaded guilty to the telephonic assault and was ordered to attend anger management classes and perform five days of community service.

Campbell recently appeared as a guest on Bravo's "Make Me a Supermodel," which concluded its freshman season last night.