A woman has died in a crash overnight on the N3 near Belturbet.
She was a passenger in a car which crashed at Drumalure at around 12.40am. She was pronounced dead at the scene.
Gardaí have said the incident has been referred to GSOC as the vehicle involved "was subject to interaction with Gardaí prior to the collision".
The driver of the car, a man, was taken to Cavan General Hospital where his injuries are described as critical.
Two other female passengers have been taken to hospital with non-life threatening injuries.
All people involved are in their 20s.
Gardaí are appealing for anyone with information to contact them in Cavan Garda Station on 049-4368800 or the Garda Confidential Line on 1800-666111.