Up to 13 people have been shot in a park in Chicago. A boy aged three and three other people were in a critical condition after the incident on a basketball court in the city's south side.
Witnesses said one or two gunmen opened fire late on Thursday night. Ten ambulances were needed to take the casualties to hospital. Police said the boy was the most seriously wounded.
In a statement Mayor Rahm Emanuel said:
"Senseless and brazen acts of violence have no place in Chicago and betray all that we stand for.
"The perpetrators of this crime will be brought to justice and prosecuted to the full extent of the law."
Chicago last year had more murders than New York City, which has a population three times bigger.
The BBC reports eight people were killed and 20 wounded nearly three weeks ago.
The Windy City saw 506 murders in 2012, compared with 419 in New York, according to a report this week by the FBI. But so far this year, the city's murder rate is down 22% from the year before.
