Four people were wounded by gunfire Wednesday in Minneapolis shooting, including a teenage boy critically wounded on a Metro Transit bus.

At 8:53 p.m., police officers responded to a report of a shooting on a Metro Transit bus at 34th and Penn avenues N. A teenage boy who had been shot in the abdomen was taken to North Memorial Medical Center in Robbinsdale, where he was in critical condition late Wednesday, police said.

A few minutes later, another juvenile male called 911 to report that he had been shot in the hand. He was taken to North Memorial. Police said they could not locate a crime scene.

No one has been arrested in either shooting. It is as yet unknown if they are related.

Earlier Wednesday, two people were wounded in separate shootings in the 3200 block of Minnehaha Avenue and at Hennepin Avenue and 7th Street downtown.

In all cases, police continue to investigate.