Firefighters were called to a skip fire at the Tesco's store in St Austell at about midnight.

Other crews were then called to a car fire at Poole Industrial Estate at about 0130 BST.

Both fires were successfully extinguished by emergency crews. The fire brigade is now looking into the possibility with Devon and Cornwall Police that they were started deliberately.

Vehicle arson

Police and firefighters were already looking into investigating three cases of arson on vehicles in Cornwall the night before.

The three incidents took place on Thursday night in Stithians, Redruth and Lostwithiel.

It is not thought that the fires are connected, but rescue crews are concerned that a total of 11 vehicle fires have occurred since Sunday, 6 July.

Cornwall Fire Brigade said it feels people who deliberately set fires fail to consider the dangers involved to the firemen who attend such emergency calls.

Divisional Fire Officer Yan Sturgis said: "Arson across the board is one of the most serious fires we can attend.

Toxic fumes

"Obviously it can damage a lot of property and can put a lot of people's lives at risk - not least our firefighters.

"A lot of cars now are fitted with gas struts that can explode and, of course, petrol tanks can explode too.

"The cars themselves are produced with products that can be produce toxic fumes."

Officers from Devon and Cornwall Police say they are keen to find out who is responsible for these incidents.