Fire officers are treating a massive blaze at a timber yard in Plymouth as arson.

The fire at Plymouth Pallet and Drum on September 16 destroyed about 10,000 wooden pallets, according to owner Andy Bennett.

Machinery and office at the site were also damaged. Mr Bennett said it was the fourth fire at the site over the past 10 years.

“It is an irresistible thing for some people to just set fire to a timber yard. It is a miracle that nobody so far has been injured.”

Mr Bennett said his total stock was about 30,000 pallets and that the cost of repairing damage would be thousands of pounds.

A senior fire officer in charge of fighting the blaze described it as “like the biggest bonfire in the world”.

A spokesperson for Somerset Fire and Rescue Service later confirmed that it was regarding the fire as suspicious.

Spectators at a nearby speedway track race meeting were forced to evacuate the area due to the heat from the blaze.

The last blaze at the pallet yard, the largest in the south-west, in 2009 was also thought to be arson.