WASHINGTON - The US Secret Service has put 11 agents on administrative leave amid allegations they brought prostitutes back to their hotel rooms while preparing for a visit by President Barack Obama, a widening scandal that may also involve five military service personnel, The Wall Street Journal reported Sunday.

The newspaper quoted Congressman Peter King, chairman of the House Homeland Security Committee which oversees the Secret Services, as saying that the agents were caught when one of the women stayed in an agent’s room past 7:00 am, in violation of hotel policy. That agent initially refused to open his door for the hotel manager, which prompted the manager to call the police, who later reported the incident to the US embassy, King said.

Also Saturday, the US Southern Command said in a written statement that five US service members assigned to the summit violated curfew and “may have been involved in inappropriate conduct.” The statement continued, “The conduct is alleged to have occurred in the same hotel where the recalled US Secret Service agents were staying.” The military personnel are confined to their quarters in Colombia and under orders not to have contact with other individuals.

They will return to the US after the mission is complete, the statement said. An investigation will follow. The Secret Service agents involved in the incident, which occurred Wednesday night, were sent home and replaced by other Secret Service personnel before Obama arrived on Friday, the Journal said, citing officials.

General Douglas Fraser, commander of the US military’s Southern Command, said that he is “disappointed by the entire incident and that this behaviour is not in keeping with the professional standards expected of members of the United States military.”

Secret Service Assistant Director Paul S. Morrissey said in a statement that 11 agents had been put on leave following interviews in Washington about the incident on Saturday. He said the group included both special agents and Uniformed Division officers.

He said the situation had “had no impact on the Secret Service’s ability to execute a comprehensive security plan for the President’s visit to Cartagena.”

Obama is attending the weekend Summit of the Americas, a gathering of dozens of regional leaders, as more details emerge about the potential security breach. Obama is pressing for trade and economic advances while addressing regional grievances against US policies, but the incident is threatening to overshadow the weekend’s agenda.