Two adult brothers were struck by a car in Gaithersburg and one of them was killed in an incident that police are investigating as a homicide.

About 1:15 a.m. Wednesday, police went to the 200 block of W. Diamond Avenue in Gaithersburg. A 34-year-old man was found dead, and his 54-year-old brother was taken to a hospital to be treated for non-life threatening injuries, Montgomery County police said.

The surviving brother told police that the two men were given a ride in a black Honda Civic earlier in the morning and were dropped off near the Gaitherstowne Plaza at Route 355 and Chestnut Street. Police are investigating why the men had gotten into the car and whether the brothers knew the people who gave them a ride.

A few minutes after they victims got out of the Honda, the men were struck while they were walking on W. Diamond Avenue. The surviving brother believes they were struck by the same car that they had been riding in, police said.

A black Honda Civic that is believed to be the vehicle involved was found at the Gaitherstowne Plaza. Investigators are trying to locate the car's owner to determine who was driving the Honda at the time of the crash.