TRAINS are having to run at a 'reduced speed' between Darlington and Northallerton.

It is understood that sheep on the line, near a stretch of the East Coast Main Line in the East Cowton area, are the cause of the problem.

Network Rail have said an operations manager will be assessing the situation, before the sheep will be moved away from the running of trains.

A spokesperson for Transpennine Express said: "The animals are between Northallerton and Darlington, our trains are running very slowly which will cause some delay - customers should check before they travel."

The line has since fully reopened and all sheep have been moved away from the railway tracks.