CHICAGO (CBS) — Three men have been killed, and at least eight more have been wounded, by gunfire in Chicago since Friday night.

In addition, police shot and killed one man, and wounded another, who allegedly pointed handguns at the officers at a block party on the Far South Side.

• In the earliest deadly incident, a man was shot and killed during a robbery just two blocks from his West Pullman neighborhood home.

The man, Alex J. Benison, 35, of the 12100 block of South Ada Street, was pronounced dead at the scene at 9 p.m. Friday, according to the Cook County Medical Examiner’s office.

Benison was standing with a group of others behind a building on the next block south from his home. About 8:45 p.m., two gunmen approached the group and announced the robbery, causing the group to begin running. Benison was shot in the face, police said.

• Around 1:10 a.m. Saturday, Jerell Butler, 26, was killed and another man was hurt when someone riding a bicycle opened fire in the Humboldt Park neighborhood.

Butler, 26, of the 900 block of North Drake Avenue, was dead at the scene, according to the medical examiner’s office. The men were standing on the sidewalk in block where Butler lived when the shooter rode by and opened fire, police News Affairs Officer Hector Alfaro said.

Butler was shot in the head and chest and was dead at the scene. The other man, 32, was shot in the upper right arm and taken in stable condition to Saints Mary and Elizabeth Medical Center.

• At 2:20 a.m. Saturday, Brian Cherney, 22, was found shot to death on a sidewalk in the Belmont-Cragin neighborhood, according to police and the Cook County Medical Examiner’s office.

Police responded call of a man down and found Cherney dead at the scene in the 4800 block of West George Street, police News Affairs Officer Laura Kubiak said.

Cherney, who lived a block away in the 4800 block of West Wolfram Street, suffered a gunshot wound to the chest.

• Around 9:40 p.m. Friday, two 18-year-old boys were shot and wounded while walking in the 1000 block of North Waller Avenue, in the South Austin neighborhood.

One victim was shot in the leg and arm, Greer said, and the other suffered a gunshot wound to the toe. A friend drove the two teens to West Suburban Medical Center in Oak Park, where they were listed in good condition, Greer said.

• Three hours later, a 28-year-old man was critically injured, when someone drove by in a sport-utility vehicle and opened fire, police said. The incident happened in the 5600 block of South Marshfield Avenue, in the West Englewood neighborhood.

The man was shot in the chest and listed in critical condition at Stroger Hospital of Cook County.

• The violence continued into the daylight hours Saturday. Around 11 a.m., a teenage boy was shot in the back and wounded in the 7000 block of South Elizabeth Street, in the Englewood neighborhood. The victim was reportedly taken to Comer Children’s Hospital at the University of Chicago in serious condition.

• And in the deadly incident involving police, officers were on the scene at a Roseland neighborhood block party when two men allegedly pointed guns at them.

Calumet District police tactical officers responded at 9:30 p.m. to calls of a man with a gun and of shots fired at the block party in the 200 block of West 110th Street, police said.

Witnesses identified three men to police officers, the statement said. As the officers approached the men and announced themselves as police, the suspects fled the scene. The officers chased on foot and two of the men pointed weapons at police.

Officers opened fire, and one of the men was fatally shot on the next block south from the block party, in the 200 block of West 110th Place, the statement said.

The unidentified man in his 20s was pronounced dead at the scene at 11:49 p.m., according to the Medical Examiner’s office.

The second man who allegedly pointed a gun was found in a nearby yard and arrested without incident, the statement said. The third suspect was arrested at the scene.

No police officers were injured and two weapons were recovered, the statement said.

“It’s a pretty simple equation. You point a gun at an officer, he’s going to defend himself,” Fraternal Order of Police spokesman Pat Camden said. Camden said attendees of the large block party were the ones to call 9-11 about the armed men, and pointed them out to responding officers.

The Sun-Times Media Wire contributed to this report.