CHICAGO — A 3-year-old boy who was among 13 people wounded in a late-night attack on a southwest Chicago park was alert when he arrived at the hospital and was apparently doing well, his family and friends said early today.

The attack late Thursday in the city’s Back of the Yards neighborhood left three victims, including the boy, in critical condition. The others were reportedly in serious or fair condition.

The child’s uncle, Julian Harris, said dreadlocked men in a gray sedan shot at him Thursday night 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.”

Police officials declined to discuss details of the investigation. Ron Gaines, a department spokesman, said no arrests had been made and that victims were being interviewed to try to determine the circumstances surrounding the attack, which happened shortly after 10 p.m.

Officer Amina Greer said at least 10 ambulances responded to the scene and took victims to several area hospitals. One victim transported himself to a hospital, police said.

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

The 3-year-old boy was taken to Mount Sinai Hospital. Hospital officials declined to disclose his condition, but fire officials said the boy’s condition was critical.

The Rev. Corey Brooks, a pastor at New Beginnings Church, spoke with family members outside the hospital 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 said there hasn’t been much gun violence in the neighborhood in recent years, adding the neighborhood went from good to bad 10 years ago, to better recently.

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.

Following a surge in homicides and shootings last year, the police department stepped up its crime-fighting efforts by, among other things, paying overtime to add patrols to some neighborhoods, including the Back of the Yards.