Four people are dead and at least 27 others hurt in shootings across Chicago since Friday evening.
Fifteen of the shooting victims were wounded in a single attack early Sunday during a party at a South Side business.
A shooter opened fire at a party, killing two people and injuring many others early Sunday morning on the South Side, police said.
The shooting happened about 4:40 a.m. in the 6700-block of South South Chicago Avenue, according to preliminary information from Chicago police.
"One of the patrons began to shoot inside the building striking multiple people," Chicago police officials said in a statement.
Fifteen people were struck by gunfire, two fatally, police said.
The victims ages range from 20 to 44 years old.
The victims were taken to area hospitals, some in critical condition.