The B660 is closed between Glatton and Holme after a tractor overturned into a ditch.
Police were called at about 11am to the B660 between Glatton and Holme following reports that a tractor had spilled oil on the road.
Officers found the tractor on its side in a ditch.
The road is closed while the tractor is recovered and the road is cleaned.
Motorists are asked to find alternative routes.
UPDATE: The road has been cleared and reopened at 1.36pm.