CHICAGO (AP) — Police say three undercover law enforcement officers were shot and wounded while driving onto an expressway on Chicago’s South Side.

The shooting occurred at 5:50 a.m. Wednesday near the 22nd District police station. Chicago police Superintendent David Brown says the two agents with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives and a Chicago officer were in an unmarked undercover vehicle.

Their injuries were not considered life-threatening. The shooting comes the same day as a scheduled visit to suburban Crystal Lake, Illinois, by President Joe Biden.

Chicago Mayor Lori Lightfoot plans to discuss gun control and the city’s violence with the president. Chicago had a violent Fourth of July weekend that saw 100 people shot, including two officers.