A fire at a pallet storage yard in Northampton, which temporarily closed a railway line, is being treated as arson by police.

Firefighters spent the night tackling the blaze in Martin's Yard, near Spencer Bridge.

About 30,000 pallets were set on fire on Monday night and at its height 70 firefighters were in attendance.

Spencer Bridge Road and the nearby railway line was closed, but both have since re-opened. A spokesman for the fire service said trains between Rugby and Northampton had been cancelled for a time.

Police are appealing for anyone who saw anything suspicious in the area immediately before the incident to contact them.