Five police officers have been taken to hospital after the vehicle they were in overturned in the Claudy area.
Part of the Glenshane Road has been partially blocked as a result of the accident, which occurred earlier this morning.
It is understood that the five PSNI officers were taken from the scene to hospital.
While their conditions are not yet known, it is believed none of the officers have sustained life-threatening injuries.
Motorists have been asked to avoid the area if possible or to expect long delays.
Diversions have been put in place on the Glenshane Road between Baranailt Crossroads and Ballyhandein Road.