WASHINGTON (AP) ― Moving swiftly, the Secret Service forced out three agents Wednesday in a prostitution scandal that has embarrassed President Barack Obama. A senior congressman welcomed the move to hold people responsible for the tawdry episode but warned “it’s not over.”

The agency announced three agents are leaving the service even as separate U.S. government investigations were under way.

The Secret Service did not identify the agents being forced out of the government or eight more it said remain on administrative leave. In a statement, it said one supervisor was allowed to retire and another will be fired for cause. A third employee, who was not a supervisor, has resigned.

The agents were implicated in the prostitution scandal in Colombia that also involved about 10 military service members and as many as 20 women. All the Secret Service employees who were involved had their security clearances revoked.

“These are the first steps,” said Rep. Pete King, R-New York, chairman of the House Homeland Security Committee, which oversees the Secret Service. King said the agency’s director, Mark Sullivan, took employment action against “the three people he believes the case was clearest against.” But King warned: “It’s certainly not over.”

King said the agent set to be fired would sue. King said Sullivan had to follow collective bargaining rules but was “moving as quickly as he can. Once he feels the facts are clear, he’s going to move.”

The embarrassing scandal erupted last week after 11 Secret Service agents were sent home from the colonial-era city of Cartagena on Colombia’s Caribbean coast after a night of partying that reportedly ended with at least some of them bringing prostitutes back to their hotel. The special agents and uniformed officers were in Colombia in advance of President Barack Obama’s arrival for the Summit of the Americas.

A White House official said Wednesday night that Obama had not spoken directly to Sullivan since the incident unfolded late last week. Obama’s senior aides are in close contact with Sullivan and the agency’s leadership, said the official, who requested anonymity because they were not authorized to speak publicly.

In Washington and Colombia, separate U.S. government investigations were already under way. King said he has assigned four congressional investigators to the probe. The House Committee on Oversight and Government Reform, led by Rep. Darrell Issa, R-California, sought details of the Secret Service investigation, including the disciplinary histories of the agents involved. Secret Service investigators are in Colombia interviewing witnesses. In a letter to Sullivan, Issa and Rep. Elijah Cummings of Maryland, the committee’s ranking Democrat, said the agents “brought foreign nationals in contact with sensitive security information.”