An explosion at a fuel storage tank caused a huge blaze at Iraq's largest refinery, inflicting burns on at least 36 workers and killing one before being brought under control, witnesses said.

A Reuters cameraman at the the Baiji refinery complex, some 180 km (110 miles) north of Baghdad, said he had seen at least one dead body and had counted at least 36 others suffering from burns.

An engineer at the government-owned plant said the fire, which had been brought under control, was an accident and not the result of an attack. "There was no sabotage. It was caused by a technical fault," said the engineer, who declined to be named. "This is the biggest fire I have ever seen at Baiji refinery. We have not had a fire like this before," said the engineer, employed at the complex since 2003, who spoke on condition of anonymity. He said one worker had been killed and 24 injured.

The initial explosion was at a storage tank containing five million litres of fuel.

The engineer said the blast had destroyed the refinery's liquefied petroleum gas (LPG) unit, where the fire had broken out, but other operations at the complex were continuing.

The refineries at Baiji in north-central Iraq have capacity of 310,000 barrels a day, according to the US Energy Information Administration, and have been operating at less than full capacity due to power cuts and other problems including fires.

In January 2007, Iraqi Deputy Prime Minister Barham Saleh said the country was losing $1.5 billion annually from attacks and theft at Baiji, which is vital to the nation's economy. The internal pipeline taking crude oil from Iraq's northern Kirkuk oilfields to the refinery has also been prone to attacks by militants seeking to disrupt the flow of oil.