Three girls aged three, 11 and 16, were killed along with a 16-year-old boy. The two girls injured were aged five and six. All six victims were black.
Police chief John Hayden said that it appeared that some of the children were hit by gunfire intended for adults who were near the children.
“What we're learning in our investigations is that there have been previous confrontations and other things that led to the incidents where the children are injured,” Mr Hayden said.
He added that the lack of cooperation from the targeted adults was hindering police investigations into the shootings. No arrests have been made in any of the recent shootings.
“The common denominator, the thing that frustrates me the most, is the fact that the adults and others of age are less than fully cooperative with our investigators,” he said.
FBI statistics released in September showed St Louis had a murder rate of 66.1 per 100,000 people in 2017, the worst rate in the nation.
Mr Hayden said about half the shootings — fatal and non-fatal — in St Louis are drug-related and another 35 per cent “are based on personal vendettas and disputes”.
The city has seen 80 confirmed homicides so far this year, up slightly from the same time a year ago. Only 23 of the crimes have been solved, in part due to lack of cooperation from victims.
All but eight of the 80 victims were black in a city that is nearly equally split between blacks and whites.
The shootings involving children in St Louis appear to be part of a national trend in recent years. A study published in December in the New England Journal of Medicine found that death by gunshot was the second-highest cause of death in the US in 2016 among people ages 1-19. The study looked at death certificates from 57 jurisdictions and found a 28 per cent increase in the rate of firearm deaths from 2013.
Police statistics show that four homicide victims in St. Louis this year were age 16 or younger, equalling the number of child victims in 2018, when there were 187 killings in total.
The four victims do not include two girls killed in separate instances this week, shootings that are still under investigation and not yet characterised as homicides, accidents or suicides. Police have released few details about any of the recent shootings.
The spate of violence involving children began on Saturday when 16-year-old Jashon Johnson was killed near Fairground Park. Police said he was shot several times.
A three-year-old girl, Kenndei Powell, was killed on Sunday night in a drive-by shooting. She and four other children were with two men on a pavement, preparing to eat pizza, when a vehicle drove by and opened fire.
Kenndei was shot in the chest. A six-year-old girl was critically wounded and remains hospitalised.
Mayor Lyda Krewson, on Twitter, called the shootings “outrageous, abhorrent, unthinkable. Unbearable pain for these families.” Her tweet suggested the possibility that the shooting was part of a feud. “No dispute/retaliation is worth this,” she wrote.
Two other child deaths this week are being called “suspicious.”
Charnija Keys, 11, was shot in the head on Monday night while inside the home she shared with her mother and older sister. Police say only that homicide detectives and child-abuse investigators are handling the case.
The family wants answers, said Arnita Norman, Charnija's grandmother. She believes her granddaughter was murdered.
“It's very frustrating because we just don't know what happened,” Ms Norman said.
Police were called just before 1.30am on Wednesday to a report of a shooting at another home. Myiesha Cannon, 16, was shot in the head. She was pronounced dead at the scene.
Latrice Cannon told the St Louis Post-Dispatch that her daughter, who just finished ninth grade, was at the house next door. Latrice Cannon heard the gunshot and ran outside, where a man in the yard shouted, “They killed her.” He never said who “they” were.
“Who killed my daughter and why?” Latrice Cannon asked.
The most recent shooting involving a child happened on Thursday night when a 5-year-old girl was shot in the arm as the car she was in was stopped at a red light. She is hospitalised and in a stable condition.
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