CHICAGO (AP) — An assault-style weapon with a high-capacity magazine was used in a late-night attack that wounded 13 people, and it's "a miracle" that no one was killed, Chicago's top police official said Friday.

Police Superintendent Garry McCarthy said such weapons belong on a battlefield, not on American streets, and that laws are needed to restrict such weapons.

McCarthy said investigators believe several people were involved in Thursday's attack, which appeared to be gang-related. Several victims are gang members. No arrests had been made.

The attack was the latest violence in a city that has struggled to stop such shootings by increasing police patrols. Chicago's number of homicides last year topped 500 for the first time since 2008.

A 3-year-old boy, Deonta Howard, was critically hurt but was alert when he arrived at a hospital and seemed to be doing well, family and friends said. Two other people were in critical condition. The others were reportedly in serious or fair condition.

The attack happened while a park was still crowded with people watching a basketball game and enjoying a warm summer night.

The child's uncle, Julian Harris, told the Chicago Sun-Times that dreadlocked men in a car shot at him before turning toward nearby Cornell Square Park and opening fire. He said his nephew was shot in the cheek.

"They hit the light pole next to me, but I ducked down and ran into the house," Harris said. "They've been coming round here looking for people to shoot every night, just gang-banging stuff. It's what they do."

Among the 13 victims were at least two minors, ages 15 and 17.

The Rev. Corey Brooks spoke with the 3-year-old's family members and said the boy was resting with his mother.

"He was talking when they first brought him in, but he's heavily sedated now," he said.

"They say he's good," said Semecha Nunn, the boy's grandmother. "They going to have to do a little plastic surgery on him, but he's OK."

Francis John, 70, said she was in her apartment when the shooting occurred. She said she went down to see what was going on, and "a lot of youngsters were running scared."

A 30-year resident, she said she was surprised by what had happened. She told the Sun-Times there hasn't been much gun violence in the neighborhood in recent years.

The shooting comes nearly three weeks after Chicago saw an outburst of violence over the Labor Day weekend that ended with eight dead and 20 others injured.