Broken down train causes disruption between Alexandra Palace and Stevenage

A Great Northern train

A Great Northern train - Credit: Archant

Hours of disruption are forecast after a train broke down and had to be terminated at Knebworth.

Great Northern and Thameslink trains have both tweeted that the broken down train has caused disruption on the fast northbound lines, which is currently blocked.

Any train running towards Stevenage “will be subject to delay or possible cancellation”, according to tweets from both companies at 6.27pm today.

The broken train at Knebworth has now been moved but delays or cancellations are still possible.

The disruption, of up to 20 minutes delay, is likely to last until 9pm, according to a statement on the Great Northern website.