Northern has warned customers to expect delays on all lines this afternoon.
The train operator said that all services had been disrupted after a fire alarm sounded at the signalling centre.
Northern operates services across the North of England, including lines through Wakefield, Leeds, Blackpool and Manchester.
In a statement, the company said: "Due to a fire alarm sounding at a signalling centre earlier, all Northern services across the network in Yorkshire may incur delays of up to 25 minutes.
"Trains are now on the move, but may continue to be delayed or amended at short notice as services return to normal.
"For passengers on station platforms, please listen for announcements or consult Customer Information Screens for up to date train running information."
Disruption is expected until at least 12.30pm today (Tuesday, September 24).