Seven people were killed and at least 39 more have been wounded in shootings across Chicago since Friday evening, including a man left in critical condition on a sidewalk near Millennium Park.

The downtown attack happened about 7:30 p.m. Saturday at the corner of Michigan Avenue and Monroe,

where a 54-year-old man was walking with two other people when he got into an argument with another male who then pulled out a gun and shot him in the head, according to Chicago Police. He was taken in critical condition to Northwestern Memorial Hospital. The shooter took off on a bicycle but was arrested nearby, police said. Detectives were questioning him Sunday.

A person of interest is also in custody for the weekend’s most recent homicide, which happened about 4:30 a.m. Sunday in the South Side Calumet Heights neighborhood. A 28-year-old man was shot in the neck in the 9200 block of South Colfax and pronounced dead at Trinity Hospital at 5:04 a.m., according to police and the Cook County medical examiner’s office. The shooting as thought to be gang-related, but police have not released details on the circumstances.

Saturday evening, a 22-year-old man was shot to death in the Englewood neighborhood. He was outside looking at a vehicle in the 1500 block of West 56th Street about 7:25 p.m. when shots rang out and he was struck multiple times, police said. Authorities have not released his name.

Early Saturday, a man was shot to death in the East Garfield Park neighborhood on the West Side. Officers responding to a call of a person down about 2:30 a.m. found the 37-year-old dead with a gunshot wound to the head in the 2600 block of West Wilcox, police said. His name has not been released.

Less than 30 minutes earlier, a man was killed and a woman wounded in Gage Park on the Southwest Side. They were outside at 2:10 a.m. in the 2200 block of West 50th Street when a vehicle pulled up and a gunman got out and opened fire, hitting 20-year-old Jose Vizcarra in the head and a 24-year-old woman in the foot, according to police and the medical examiner’s office. Vizcarra, of the 400 block of North Hamlin, was dead at the scene, authorities said. The woman was taken to Mount Sinai Hospital in fair condition.

Friday night, a 19-year-old man was killed and a 20-year-old man critically wounded in another Englewood neighborhood shooting. A gunman walked up to them about 8 p.m. in the 5600 block of South Racine and opened fire, hitting Izael McKenzie in the head and the older man in the back, authorities said. Both were taken to Stroger Hospital, where McKenzie died at 8:44 p.m. He lived in the 5600 block of South Throop. The other man was in critical condition, police said.

About 5:35 p.m. Friday, 21-year-old Joaquin Gonzalez was shot in the chest and pronounced dead at the scene in the 2600 block of West Haddon in the Humboldt Park neighborhood on the West Side, authorities said. Police have not provided details on the circumstances of the shooting, but an autopsy ruled Gonzalez’s death a homicide. He lived in the 7700 block of South Peoria.

The weekend’s first fatal shooting came 10 minutes before that in the Auburn Gresham neighborhood on the South Side, where someone chased 56-year-old Carl Jackson into his apartment building in the 1000 block of West 77th Street and shot him repeatedly, authorities said. Jackson died at the scene.

The most recent nonfatal shooting happened about 4:20 p.m. Sunday in West Englewood, where someone walked up to a 17-year-old boy in the 1900 block of West Marquette and shot him in the right shoulder, police said. He was taken in critical condition to Christ Medical Center in Oak Lawn.

At least 35 more people have been shot in other city attacks since 4:15 p.m. Friday.