(CNN)At least three people were killed and four others injured in a shooting Monday night in St. Louis, Missouri, officials said.
Police Commissioner John Hayden said there was no known motive for the shooting, but that officers were canvassing the area in the city's Ville neighborhood and looking for any video that might have been recorded around the scene.
"It's very early in the investigation," he said during a news conference.
Two of the bodies were found outside of a convenience store and the other victim apparently collapsed in a nearby schoolyard, the commissioner said.
Hayden said the deceased were "adult males, approximately in their thirties." He did not disclose the condition of those who were injured.
The St. Louis shooting comes in the heels of another violent weekend in the US.
At least seven people were killed and at least 45 were injured in 10 separate mass shootings between Friday and Sunday night, according to the Gun Violence Archive. Among the victims were at least two children, a 10-year-old and a 15-year-old, police said.
CNN defines a mass shooting as four or more people shot, not including the shooter.