Three undercover law enforcement officers were shot and wounded Wednesday morning while driving onto an expressway on Chicago’s South Side, and detectives were questioning a “person of interest” about the shooting, police said.

The shooting occurred at 5:50 a.m. near the 22nd District police station in the city’s Morgan Park neighborhood. The three were in an unmarked undercover vehicle on their way to an assignment when they were shot, Chicago police Superintendent David Brown told reporters.

Two of the officers are agents from the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, and one is a Chicago officer, Brown said. Their injuries were not considered life-threatening. A department spokesman told the Associated Press that a person of interest was in custody and being questioned by detectives. He did not provide any other details.

The shooting came ahead of a scheduled visit to suburban Crystal Lake, Illinois, by President Joe Biden. Chicago Mayor Lori Lightfoot has said she plans to discuss gun control and the city’s violence, which has included an increase in shootings this year, when she meets with the president.

A Justice Department spokesperson said Attorney General Merrick Garland was briefed on the shooting and aboard Air Force One on the president’s flight to Chicago, White House press secretary Jen Psaki said the administration was also “monitoring the situation in coordination with the Department of Justice and ATF.”

Psaki said Biden planned to meet with both Lightfoot and Illinois Gov. J.B. Pritzker.

“I will note, in terms of efforts the president has under way to address the rise in violence we’ve seen over the last 18 months, including in Chicago, there are a number of steps that impact Chicago directly,” Psaki said.

At a morning press briefing, Brown declined to talk about what the officers were working on. He did not say whether the shooter or shooters knew that they were officers, and department spokesman Tom Ahern later said detectives had not yet interviewed the three officers to determine if they believe whoever shot them knew they were law enforcement officers.

The officers, Brown said, were driving on an onramp to Interstate 57 when they were “fired upon from the street.” One of the ATF agents was shot in the hand and the other was struck in the torso, Brown said from outside a hospital where the officers were taken. He said the Chicago officer was struck on the back of his head but that “it appears to be a graze wound.”

The shootings come a day after police reported that 100 people were shot in Chicago — including two police officers who were wounded while trying to break up a crowd — over the long Fourth of July weekend.

With Wednesday’s shooting, 36 Chicago officers have been shot or shot at this year, Brown said.

“This is a very challenging time to be in law enforcement but they are rising to the challenge of doing all they can. And the work they do is extremely dangerous,” Brown said.

The holiday weekend shootings included 18 homicides. The bloodshed was comparable to the long Fourth of July weekend last year, when 17 people were fatally shot and 70 more were wounded.

(AP)