WASHINGTON - The Obama administration is investigating allegations that two senior Secret Service agents, including a top member of the president's protective detail, drove a government car into White House security barricades after drinking at a late-night party last week, an agency official said Wednesday.

Officers on duty who saw the March 4 incident wanted to arrest the agents and conduct sobriety tests, according to a current and a former government official familiar with the incident. But the officers were ordered by a supervisor on duty that night to let the agents go home, said these people, who spoke on the condition of anonymity to discuss the sensitive matter.

The episode presents an early test for the Secret Service's new director, Joseph Clancy, who was appointed by President Obama last month after a string of security lapses at the White House and other embarrassing missteps and had vowed to restore the agency's once-stellar reputation.

Clancy on Monday directed that the inquiry be led by the Department of Homeland Security's inspector general, in part because the incident involves such senior officials, a law enforcement official said.

Agency spokesman Brian Leary confirmed the investigation after questions from the Washington Post, saying the Secret Service was "aware of the allegations of misconduct involving two of our employees." He declined to specify which allegations are the focus of the inquiry.

"If misconduct is identified, appropriate action will be taken based on established rules and regulations," Leary said. He added that the agency "will fully cooperate" with the inspector general's office.

An administration official said that in "recent days," the White House was "made aware of the allegations and the steps being taken by the Secret Service to ensure that the incident is thoroughly investigated."

The agents under investigation are Mark Connolly, the second-in-command on Obama's detail, and George Ogilvie, a senior supervisor in the Washington field office.

They declined to comment through the Secret Service spokesman.

An agency official said the two employees had been moved to "nonsupervisory, nonoperational assignments." They were not put on administrative leave, which has been a typical procedure when agents are under investigation.

The incident happened about 10:30 p.m. on the White House compound, as Metropolitan Police Department and Secret Service officers were trying to clear the scene due to an investigation of a suspicious package, said people familiar with the incident.

Witnesses reported that the car's overhead flashing lights had been activated and both agents were showing their badges to get through the section of the grounds that had been closed off, according to people familiar with the incident.

The vehicle ran through security tape before hitting barricades, which an agency official said were set up temporarily during the investigation of the package.

Secret Service rules prohibit turning on flashing lights without a security reason and driving a government vehicle after drinking alcohol.

The two men had been attending a party at a nearby Washington bar to honor the retirement of departing Secret Service spokesman Edwin Donovan.

Two people familiar with the incident said it was likely captured on Secret Service video. They said all of the agents' activities on that part of the compound would have likely been streamed live to the agency's emergency command center.

The incident violated security protocols, according to several veteran agents.

If a civilian drives through a White House security barrier, officers are trained to release an attack dog or point loaded guns at the driver.

Last week's incident is the first major misstep to take place since the management shake-up that began in October, when Director Julia Pierson resigned in the weeks after a man was able to jump the White House fence and race through much of the mansion's main floor.

Clancy, a 27-year agency veteran before taking a top security post at Comcast, took over as acting director, moving later to force out much of the senior management team.