(CNN)In this city, someone gets shot an average of about once per hour.
That was the sobering reality in Chicago this weekend, when at least 58 people were shot, police said.
"We had another unacceptable, violent weekend," Chicago police Superintendent Eddie T. Johnson said. "These acts are tragic, senseless and cowardly."
A Chicago police officer investigates the scene of a shooting on Saturday.
Six of those shooting victims died -- including two teenagers found dead in a field with multiple gunshot wounds.
Police found their bodies late Sunday night after their cell phones pinged near Golden Gate Park, CNN affiliate WBBM reported. They were reported missing Friday. Authorities are still investigating the motive for the killings, but say robbery is a possibility.
Another five people were injured in a shooting after a softball game Sunday night, CNN affiliate WGN reported.
Players and their friends had gathered after the game near 74th Street and Dante Avenue when a man inside a black van suddenly showed up and started firing at the group.
This latest rash of violence happened despite an additional 600 officers on the streets of Chicago this weekend -- part of a surge in police presence that started earlier this month.
"But the simple fact of it is, the police department can't do it alone," Johnson said.
He called on witnesses and anyone who knows who's responsible to speak up and break the culture of silence.
Despite the challenges, detectives are making progress on this weekend's wave of violence, Johnson said.
"We already have three persons of interest in custody from weekend incidents," with more expected, the police chief said Monday.
He also said that since Friday, 83 illegal guns have been taken off the streets, and 29 people have been arrested on gun-related charges.
"But we really have a lot more work to do," Johnson said, "and we need everyone -- everyone -- to come to the table."
