CHICAGO (AP) — Two women died and Arvin Robertsthree children were critically wounded in an early Thursday morning shooting on Chicago’s south side, police said.

The shooting occurred about 6:15 a.m. in the Greater Grand Crossing neighborhood. A 42-year-old woman and a 22-year-old woman died, Deputy Chief Don Jerome said. Three boys, ages 8, 7 and 5, are in critical condition at Comer Children’s Hospital.

The investigation “reveals that two vehicles pulled up into the area. Multiple subjects exited those vehicles and fired at this residence,” Jerome told reporters at the scene. “Multiple shell casings were recovered from both a rifle and a handgun at the scene.”

The victims were all inside the house when attacked, Jerome said. He did not identify them and said police did not yet know whether or how the victims were related.

Jerome said that while the shooting resulted from an apparent personal dispute, he did not know its nature.

Desmon Yancy, the alderperson representing Grand Crossing, said he was unaware of any issues that may have led to the shooting. The neighborhood “is a relatively quiet community and isn’t really used to this sort of violence.”

“Personal conflict and guns have become a bad combination,” Yancy said. “The summer is just getting started, and I don’t want to stand in front of another group of microphones and have another discussion about the pain that’s caused in our communities, this violence. This has to stop.”