Train services have been disrupted after a broken down freight train blocked the line.
Passengers using Northern Rail's services between Newcastle and Nunthorpe, which travel via Sunderland, Seaham and Hartlepool, have been told trains are expected to be cancelled, delayed or revised until around 4pm.
A spokesman for the company said: "Due to a fault with a freight train on the line near Billingham, all services on this line and in this direction only are currently blocked between Hartlepool and Billingham.
"Staff are due on site soon to attempt to rectify this issue, however, at this time no estimation as to when normal service will resume can be provided.
"For passengers on station platforms, please listen for PA announcements or consult customer information screens for up to date train running information."
It added for live information, visit www.northernrail.co.uk/stations and select the station of travel.