Three girls sitting in a car with their mother were shot by a man who police say was firing at rival gang members, in a violent start to the July 4 holiday week that is typically among the bloodiest stretch of days on Chicago's calendar.

None of the girls — ages 5, 14, and 15 — was killed in the shooting Sunday, but police spokesman Anthony Guglielmi said the 14-year-old was shot in the abdomen and listed in critical condition.

The 15-year-old was shot in the thigh and the 5-year-old was shot in the arm. Police said their injuries were not considered life threatening. Three others — two adults and one teenager — were also shot. The woman was in serious condition and the other two were listed in good condition.

The fact the gunman — with a bandanna covering much of his face — simply leaned out the car window and opened fire indiscriminately in a crowded area on the city's West Side, illustrates the willingness of gangs to wage war regardless of who is around. It also explains why the police department has, according to Guglielmi, assigned an additional 1,700 police officers to street duty during the coming long holiday weekend.

Last year, when July 4 fell on a Tuesday, more than 100 people were shot between the previous Friday night and early July 5. This year, the holiday falls on a Wednesday, giving police two weekends in which they must contend with an increased possibility of gunfire.

Sunday night's shooting also underscores that gang violence can erupt without notice, despite a concerted police effort to suppress it.

"We did some targeted raids (with federal drug agents) in early June and went back again last week, and made about 50 arrests," he said. "We were focusing on the West Side and trying to destabilize a gang conflict and violence had slowed down a bit."

Guglielmi said no arrests have been made and the gunman has not been identified, but he that detectives believe the targets were three people, including two documented gang members: a 26-year-old man with nine felony arrests, nine misdemeanor arrests and six convictions, and a 17-year-old male with five felony arrests as a juvenile.

The shootings happened after a six month period that was far less violent than the same period during the previous two years. According to police statistics, there were 252 homicides in the first six months of this year — 79 fewer homicides than were reported during the same period last year and 73 fewer than the same period during 2016. Similarly, there were at least 270 fewer shooting incidents during the first six months of the year than there were during the same period during either of the two previous years.