Two people are dead and two others are seriously injured after an unknown vehicle ran their car off the road from behind in central Missouri and took off.

The Missouri State Highway Patrol says 53-year-old Ronald Harvey of Green Ridge was driving a 1997 Mercury on U.S. 50 in Johnson County at 12:28 a.m. Sunday when a second vehicle struck it from behind.

The patrol says the impact knocked the Mercury off the highway, where it overturned and struck a tree. Investigators are looking for the second vehicle, which left the scene.

Harvey and a 54-year-old passenger, Vickie Brandkamp of Green Ridge, were killed in the crash. Two 47-year-old passengers in Harvey’s car were taken to a hospital in serious condition.

None of the four were wearing seatbelts.