in the nation's capital.
"I can tell you that it's an ongoing investigation and that 13 people were shot," Chicago police department spokeswoman Amina Greer said on Friday.
No arrests have been made so far, Greer said.
"At this time, we believe the motive for the shooting to be gang-related," she said. Gunfire rang out at about 10:15pm Thursday, Greer said.
Mayor Rahm Emanuel canceled two cabinet meetings in Washington on opportunities for Chicago and was headed back to his city after being notified about the shooting, his press office said.
"Senseless and brazen acts of violence have no place in Chicago and betray all that we stand for," Emanuel said in a statement. "The perpetrators of this crime will be brought to justice and prosecuted to the full extent of the law."
Police said that besides the 3-year-old, the injured ranged in age from 15 to 41.
Officials and emergency responders tend to a victim at the shooting scene in Chicago. AP photo
Greer was unable to confirm local media reports that said four of the gunshot victims injured in the shooting on a basketball court, including the 3-year-old, were listed in critical condition in area hospitals early Friday.
Chicago has been plagued by gun violence in recent years, with more than 500 murders in 2012, according to a report this week by the FBI.
A Chicago Police detective collects crime scene tape from the scene in a city park on the south side of Chicago. AP photo
By comparison, New York City, which has a population three times the size of Chicago, had 419 murders in 2012, the FBI said.
One Chicago murder this year that caught national attention was of Hadiya Pendleton, 15, an honor student killed at a park just days after she performed at a January presidential inauguration event in Washington.
Other notorious Chicago killings include the death of a 7-year-old girl last summer at her mother's candy stand and the shooting of a 6-month-old baby last March by a gang member who was aiming at her father.
The Chicago fire department hoses down the scene where 13 people, including a 3-year-old child, were shot in Chicago. AP photo