ATLANTIC CITY — Federal authorities searched the home of Mayor Frank Gilliam Jr. for more than four hours Monday morning.

Speaking to reporters outside Gilliam’s home, FBI Special Agent Jessica Weisman said the bureau and the Internal Revenue Service were there “in an official capacity to execute a search warrant.” Weisman did not say what authorities were looking for in the mayor’s Ohio Avenue residence.

Gilliam, a Democrat, was elected mayor in 2017. His short, but troubled, tenure has included allegations of campaign fraud, theft and a fight involving another elected official outside a casino nightclub.

Agents arrived at the mayor’s house shortly before 8 a.m. Monday and left around noon. Gilliam, 48, was home during the search.

About 30 minutes after investigators departed, Gilliam left his home in a silver Mercedes-Benz SUV and declined comment to reporters across the street. He could not be reached for comment later.

Over the course of the search, close to a dozen agents entered the tan two-story home and carried out several cardboard boxes, computers, including an Apple desktop, and a printer, before loading them into unmarked federal vehicles. Authorities unloaded the seized property at the FBI office in Northfield.

Crowds of onlookers were clustered on street corners discussing the raid and its possible implications, as media gathered across the street.

A small group of supporters, some crying, huddled in prayer near the corner of Ohio and Morningside avenues. When television cameras approached the group, one man became agitated and had to be restrained by others.

Christina Bevilaqua, Gilliam’s deputy chief of staff, said the office had no comment. The mayor’s office at City Hall was not subject to federal investigation Monday.

The mayor’s staff did not identify Gilliam’s defense attorney.

City Hall was open Monday and the mayor’s staff continued to handle official business, Bevilaqua said.

The state Department of Community Affairs, which oversees the day-to-day operation of the city, said it is monitoring the situation.

“We cannot comment on an ongoing investigation,” said Lisa Ryan, spokeswoman for the department. “We remain focused on the people of Atlantic City and ensuring that their needs are met.”

Council President Marty Small Sr., who challenged Gilliam in the 2017 Democratic primary, would not comment on the raid or the mayor’s future following Monday’s events. Small added that he spoke with Lt. Gov. Sheila Oliver — who also serves as commissioner of the DCA — Monday morning about “city business” but declined to elaborate.

“I’m going to keep (City) Council focused, as we have been,” he said. “We’re going to continue handling the business of the city of Atlantic City and the other things will play out on their own.”

Should Gilliam resign or be forced from office, Small would become mayor for an unexpired term until a special election is held.

Councilman Kaleem Shabazz declined to comment “except to say we’re going to keep working to move Atlantic City forward.”

Gwen Callaway Lewis, of Penrose Avenue, said it was “shocking” to see the FBI in the neighborhood.

“That means it’s serious,” she said.

She added that it was “appalling” that the mayor has brought a federal investigation into the neighborhood.

“I wasn’t surprised because I know his character,” Callaway Lewis said.

An Atlantic City police officer parked in front of the house stood guard and kept bystanders back while agents carried out the raid. After federal investigators left the house, five marked city police cars were parked outside the house until Gilliam departed.

Since taking office in January, Gilliam’s tenure as mayor has been controversial. In April, a Superior Court judge dismissed a criminal complaint filed by the Atlantic City Democratic Committee against Gilliam surrounding the alleged theft of a $10,000 campaign check. Gilliam claimed it was a mistake and the check was returned to the committee.

At-Large Councilman George Tibbitt, who ran on a joint ticket with Gilliam in 2017, also accused the mayor of depositing campaign checks with his name on them. Tibbitt told The Press on several occasions that the FBI had interviewed him multiple times this year related to the missing campaign contributions.

Tibbitt could not be reached for comment Monday.