Police have initiated a negligent injury case after a Waikiki patrol officer trying to make a traffic stop in a marked vehicle was hit by a motorcyclist.

The 37-year-old driver of the motorcycle was taken in critical condition to the  hospital. However, police said his condition was upgraded to serious, but stable after he was hospitalized. The officer was not injured.

The police officer, a six-year veteran, has been placed on desk duty while police investigate the incident, which is classified as a second-degree negligent injury case.

Police said the officer was headed into Waikiki just before noon Wednesday on Kalakaua Avenue when he observed when a traffic violation near Ena Road.

The officer was executing a U-turn through a median when the motorcycle and police car collided, police said.