Damage is estimated at tens of thousands of pounds

The damage from the fire at Plymouth Pallets at Marsh Mills is estimated at tens of thousands of pounds.

The fire, which broke out at about 0815 on Sunday, follows a similar incident at the yard a year ago.

Police want to speak to a group of about a dozen runners, wearing red bibs, who reported the fire and said they had seen a group of five youths in the area.

There is also a suggestion that a youth was seen dropping a burning jacket into the river.

Detectives are investigating whether the fire is connected to another suspected arson in Plympton.

That left a warehouse at the packaging firm DS Smith-Boon, in Newnham Road, severly damaged. It also contained pallets.