CHICAGO (CBS) — Two men were killed and at least 20 other people have been wounded in shootings across Chicago since Friday afternoon, marking a violent start to the Christmas holiday weekend.

The most recent fatal shooting happened at 5:31 p.m. Saturday in the Roseland neighborhood on the Far South Side. A witness said a 19-year-old man was standing in the 11200 block of South Michigan when someone got out of a dark-colored SUV and fired shots before taking off in an unknown direction, according to Chicago Police and the Cook County medical examiner’s office. The man suffered a gunshot wound to his back and was pronounced dead at the scene at 5:42 p.m. He identity has not been released, pending notification of his family.

About three hours earlier, a 21-year-old man was killed and a 25-year-old man was wounded in an Austin neighborhood shooting on the West Side. The men were sitting on a back porch at 2:34 p.m. in the 5200 block of West Ferdinand when another male walked up, fired shots and ran off in an unknown direction, authorities said. The younger man suffered multiple gunshot wounds to the head and body and was pronounced dead at the scene at 3:12 p.m. His identity has not been released. The older man was shot in the ankle and taken in good condition to Stroger Hospital.

The most recent nonfatal shooting happened about 3:50 a.m. Sunday on the Near West Side. A 26-year-old man was the front passenger in a vehicle, stopped at a light in the 1200 block of West Van Buren when a Dodge Challenger pulled alongside and the man got into an argument with the other driver, police said. The driver of the Challenger fired several shots, and the man was struck in the right hip. The suspect then sped away, heading west on the Eisenhower Expressway (I-290). The man was driven to Rush University Medical Center, where his condition was stabilized. Police said he was not cooperating with investigators.

At least 18 other people have been wounded in shootings across Chicago since the start of Christmas weekend Friday afternoon.

Last year, 59 people were shot in Chicago over the holiday weekend, leaving 11 dead.

(Source: Sun-Times Media Wire copy; Chicago Sun-Times 2017. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)