Milwaukee police are investigating three separate shooting deaths that occurred in a span of 10 hours. At least one suspect remains on the loose.

Police said the violence began Friday about 5 p.m. That's when they say an 18-year-old tried to rob a man and was killed in a subsequent shootout. A WITI-TV report said the other man was wounded in the arm.

In the second case, authorities said a suspect walked up to a 38-year-old man at a gas station just before midnight and shot him several times. A message left with police asking whether the suspect is in custody was not immediately returned.

The third victim was a 26-year-old man who was shot once in the upper body. Police have no suspect in that case.