CHICAGO (AP) — An argument in a house on Chicago’s South Side early Tuesday erupted into gunfire, leaving four women dead and four other people injured, police said.

The shooting happened at 5:42 a.m. in the city’s Englewood neighborhood, police said, and no arrests were immediately made. Police had few details about the victims, but it appeared that none of them were juveniles.

Detectives were still trying to determine if there was more than one gunman and that they were still trying to find witnesses, police spokesman Tom Ahern said. A young child was removed safely from the house and placed in protective custody, he said.

The shooting comes a few days after a woman was killed and nine other people were injured when two men opened fire on a group standing on a sidewalk on Chicago’s South Side. Police said that no arrests have been made in that shooting, which was among mass shootings over the weekend in three states that stoked concerns that a spike in U.S. gun violence could continue into summer as coronavirus restrictions ease and more people are free to socialize.

A database compiled by The Associated Press, USA Today and Northeastern University that tracks mass killings — defined as four or more dead, not including the perpetrator — shows Tuesday’s shooting in Chicago is the 18th mass killing, of which 17 were shootings, so far this year in the U.S.

The shooting happened in Englewood, which has long been one of the most violent communities in Chicago. It comes as the city is experiencing more homicides this year compared with the same period last year. There were 282 homicides in Chicago as of June 13, compared with 269 for the same period last year.

Later in the morning at an unrelated press conference, Chicago Mayor Lori Lightfoot said the city needs federal to help combat violence and said that the White House on Tuesday morning had reached out to offer assistance.

“We must acknowledge this for what it is — a tragedy that’s ripped apart families and inflicted intense trauma,” Lightfoot said.

Identities and the ages of the dead women weren’t immediately released.

The four injured in Tuesday morning’s shooting included a 25-year-old man who was shot in the back of the head and another man who was shot in the back of the head. Their conditions were unknown, according to police. A 23-year-old man who was shot in the back and a woman who suffered an unspecified gunshot wound were both in critical condition, police said.

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