WASHINGTON (CNN) -- More Secret Service resignations are expected Thursday or Friday in the wake of an alleged prostitution scandal in Colombia, the chairman of the House Homeland Security Committee told CNN.
Three Secret Service members already are leaving the agency, but the fallout continued Thursday with congressional demands for more details about what happened in Cartagena before last week's Summit of the Americas.
Republican Rep. Peter King of New York said four investigators from the homeland security panel he heads are examining the incident and could travel to Colombia if necessary.
"It does appear that you will have more employees leaving either today or tomorrow." King said, adding he didn't know the exact number, "but I do expect more employees to be leaving the Secret Service, more agents to be leaving the Secret Service."
King also said that despite concerns that the contact with Colombian nationals could have led to security breaches regarding President Barack Obama's activities, "from everything we know, nothing was compromised."
A total of 11 members of the special security agency that protects the president and other top officials have been linked by the agency to the controversy, including the three who are leaving.
One of those is a supervisory employee who is being allowed to retire, and another employee has resigned, the agency said.
A third agent, another supervisory employee, is being pushed out, with the agency proposing he be removed. A U.S. official said on condition of not being identified that the agent plans to fight his ouster.
The other eight members allegedly involved in the scandal are on administrative leave with their security clearances suspended, according to the agency.
All the employees are accused of bringing prostitutes to their hotel in Cartagena ahead of last week's visit by Obama, who was there to attend the pan-American summit.
Rep. Elijah Cummings, D-Maryland, told CNN that Secret Service Director Mark Sullivan indicated to him Wednesday that a culture of pride at the agency would likely cause implicated agents to resign.
"I said, 'Is it possible that these men would resign?' He said he had no doubt that they would, that they probably would," Cummings said of his conversation with Sullivan that occurred before the first three departures were announced. "Why? Because of the culture. They have this pride, they don't want any bad apples and so it probably would be so uncomfortable to them that they would leave. So, yesterday's actions with regard to folks leaving and being fired did not surprise me one bit."
According to sources, the alleged prostitutes, the youngest of whom were in their early 20s, had all signed in at Cartagena's Hotel El Caribe, where the Secret Service members apparently stayed, flashing their local ID cards.
But one of the women later was involved in a dispute about how much she was allegedly to be paid for the night.
That dispute brought the incident to light and sparked controversy in both countries.
Former Colombian President Alvaro Uribe told CNN on Thursday that he rejects "the idea that Cartagena is a destination for tourists seeking prostitution or illicit drugs," saying the international community should respect Cartagena for its history and beauty.
"Nobody in Colombia thought that the Secret Service of the United States was going to make the decision to promote prostitution," Uribe said. "Therefore, this is not the fault of our government. ... It is a lack of ethics (on the part of) the Secret Service of the United States."
A review board is expected to be created to determine whether the incident is an isolated one or is emblematic of a broader agency culture.
In addition, the House Oversight Committee's leaders sent a letter to the Secret Service requesting specifics about what happened before, during and after the incident.
Senate Majority Leader Harry Reid, D-Nevada, harshly criticized those involved in the Colombia scandal.
"There is not a bill we can pass to cause people to have common sense," Reid told reporters Thursday. "I mean, think about this -- people that are here to protect the president, they go to Colombia and have a fight with a prostitute over how much she should be paid? That's either really stupid or a total lack of common sense."
Sen. Pat Leahy, the Judiciary Committee chairman, told CNN he would make the issue the focus of a hearing planned for next week with Homeland Security Secretary Janet Napolitano.
"I want to make sure we don't have a culture that would allow this," the Vermont Democrat said. "What happened there is as dumb an action as you can imagine."
Adding that he is a "big fan" of the Secret Service, Leahy said: "If this is just a small aberration, then let us know that. If it goes further, we need to know that, too."
At the White House, Press Secretary Jay Carney fended off attempts by reporters to elicit administration comment on whether more Secret Service personnel should lose their jobs, including Sullivan.
"We are not going to prejudge outcomes and discuss the future of this agency in a press briefing while this investigation is going on," Carney said. "The fact of the matter is this is an incident that requires investigation. The Secret Service has acted with speed in addressing the matter, investigating the matter, holding people accountable, and continuing to push forward with the investigation."
However, veteran Republican Sen. Jeff Sessions of Alabama said the Secret Service scandal and other high-profile problems such as recently revealed spending abuses in the General Services Administration signal a lack of leadership by Obama.
"The president needs to assert discipline, management directions throughout the executive branch and presidents are to be held responsible," Sessions said. "They also need to be responsible for insisting from the top to the lowest employee that not one single dollar will be wasted in this government. It's the taxpayer's money. It's been sent here to be used for good causes, not to be wasted. Now, I don't sense that this president is showing that kind of managerial leadership."
As many as 10 U.S. military personnel from all branches of the armed forces also are being questioned about potential misconduct, including five members of America's elite Army Special Forces.
The military personnel were sent to Colombia to support the Secret Service. A military official who spoke on condition of anonymity because of the ongoing investigation told CNN that two of those being questioned are Marines and that Air Force and Navy personnel also are being questioned.
The military members being investigated are not likely to deploy until the matter is resolved, military officials said Thursday. While no formal order bars their deployment, it's unlikely while investigators seek answers about what happened in Cartagena, the officials said.
The five Army Special Forces soldiers being questioned are from the 7th Special Forces Group based at Eglin Air Force Base in Florida, the officials said. The group operates mostly in South America, the officials said.
Its mission includes aiding foreign internal defense, special reconnaissance, counterterrorism, counter-proliferation and unconventional warfare, according to information on the 7th Special Forces' website.
Obama has said he expects a "rigorous" investigation.
"The only way they will prevent this from happening again in the future is to find out if this is one particular case or if it's a pattern," said King said Wednesday.
"We're working and doing our own investigation and whatever we need from the Secret Service we've been getting," he said. "We want a minute-by-minute, hour-by-hour account of what happened, how it happened, what went on, who knew what was happening. And I have no doubt the Secret Service will give us that."
At least one congressman, U.S. Rep. Randy Forbes, R-Virginia, has called for Sullivan to be replaced as head of the Secret Service.
"There's only so many strikes you get, in baseball it's three," said Forbes, a senior member of the House Armed Serves Committee, referencing a 2009 security breach in which a Virginia couple crashed Obama's first White House state dinner, as well as apparent agency overspending in that same year.
"I think he's had three," Forbes added. "I think it's time to put somebody else in there to make sure we're getting a different culture in the Secret Service."
However, King and others came to the defense of Sullivan, who has directed the Secret Service since May 2006 and been with the agency since 1983.
Leahy said he has been in close touch with Sullivan and believes the agency director is taking "serious action" to investigate the incident, noting polygraph tests have been administered, while House Oversight Committee Chairman Rep. Darrell Issa, R-California, said he has a high level of confidence in Sullivan.
Sullivan has told subordinates to use "all tools available" to conduct the investigation, one source said.
The Secret Service agents and officers being investigated range in experience from relative newcomers to nearly 20-year veterans, two government officials with knowledge of the investigation said Monday.
Each agent was offered an opportunity to take a polygraph test, according to a U.S. official. Some of the agents and military personnel maintain they didn't know the women were prostitutes, the official said.
Even so, King said, "it was totally wrong to take a foreign national back to a hotel when the president is about to arrive."
While soliciting prostitution is in most cases legal for adults in Colombia, it is considered a breach of the Secret Service's conduct code, government sources said. Military law also bars service members from patronizing prostitutes, engaging in conduct unbecoming an officer or, for enlisted personnel, conduct "prejudicial to good order and discipline."
CNN's Barbara Starr, Rafael Romo and Tom Cohen contributed to this report.