Norwegian rescue officials say the trailer of a tanker truck with some 16,500 litres (4,290 gallons) of fuel got loose and crashed into a subsea tunnel wall, causing a huge explosion. No one was seriously hurt.
The tunnel has been closed to everyone except firefighters.
Rescue spokeswoman Magni Brandsoey said the truck driver was able to get out and call a rescue center. It was not clear how the trailer got loose.
Photos posted on Norwegian media show a huge black billow of smoke in the mountainous area in western Norway.
The explosion happened around 11 am (0900 GMT) in a 1,901 meter (6,237 feet) subsea tunnel linking two islands in the Sogn og Fjordane county.
