MINNEAPOLIS (AP) — The Minneapolis Police Department has launched an internal affairs investigation after an officer was caught on video punching a Black teenager.

A bystander recorded the confrontation as it unfolded in north Minneapolis Wednesday evening. Police Chief Medaria Arradondo says it followed a violent carjacking in New Hope. The Racial Justice Network is circulating the nearly 4-minute Facebook video.

The group contends it shows that while one Black teenager was being arrested, officers surrounded another Black teenager, with a white male police officer winding up and punching the teenager in the head. The video does not make clear what preceded the punch.