Two people have been seriously injured in an accident on the A46 in Market Rasen.
Police were called to Caistor Road at 4.40pm, where a car and a motor cycle had collided.
The two people who were injured were taken to hospital.
Motorists are being warmed the road is likely to be closed for some hours and diversions are in place.
It is believed a black Seat Toledo and a black Honda motor cycle are the vehicles involved.
Anyone who was in the area just before 4.40pm this afternoon and saw either the car or the motor cycle before the collision, or saw the collision itself, is asked to contact police on 101 or the witness hotline on 01522 558855, quoting incident 353 of 7/8/2016.