CHICAGO (WGN) – A Chicago police officer and two federal agents were shot Wednesday while conducting an investigation.

The Chicago officer and the agents, who were with the Bureau of Alcohol, Tobacco, Firearms and Explosives, were working together in an unmarked vehicle in the city’s Morgan Park neighborhood around 5:50 a.m. when shots were fired at them as they were driving onto an expressway.

According to Chicago police Superintendent David Brown, who said the three were on their way to an assignment, the shots came from the street. He declined to discuss what the officers were working on.

None of the injuries were life-threatening. One of the ATF agents was hit in the hand, and the other was struck on their side near their arm. The Chicago officer was grazed on the back of the head.

No arrests have been reported.

The Chicago officer was the 36th cop to be shot or shot at this year, Brown said. Police could not provide further information due to an ongoing investigation, he 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 shooting comes the same day as 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.

On Tuesday, police reported that 100 people were shot in the city over the Fourth of July weekend, including two police officers who were wounded while trying to break up a crowd.

The Associated Press contributed to this report.