The Italian fire service tweeted this picture of the fire but said no-one was injured.
Witnesses said they saw a 'ball of fire' hundreds of metres high.
The fire broke out at the Sannazzaro de' Burgondi refinery, one of the biggest in Italy, just before 4pm local time.
The news agency ANSA said a cloud of black smoke was visible for six miles from the site of the blast in northern Italy.
The refinery is owned by Italy's national oil company, ENI, who said nobody was injured and there had not been an explosion.
But Angelo Bonelli, a Green MP, said: 'Too many refineries in our country suffer major accidents that pose an urgent need to investigate.'
He said today's accident was the third at the Sannazzaro refinery. There were fires on 2 and 6 July and he said the unions at the plant had denounced the lack of effective security due to staff shortages.
Emilio Sala, a farmer who lived nearby, said: 'We heard the sirens of the refinery and saw the flames, which at first were not very high. Then there was a series of bursts, with a lot of smoke and flames that reached far beyond the height of the chimneys, to more than 60 metres.'
He told the Ilfattoquotidiano website: 'We were afraid that the fire would spread to the next reactor but luckily the internal systems must have worked. They could see the water cannons in action. This is definitely the biggest fire they have had there.'
A local councillor, Giulio Gallera, said the situation was now under control.
But they are checking 'for possible health effects of people living near the refinery who may possibly have inhaled fumes'.
Ambulances were in place to respond to any health concerns from nearby residents.
ENI said it was monitoring air quality around the refinery and would turn the data over to the authorities.
The incident occurred at 3.40pm in a recently built part of the refinery.
Source: Associated Press
..do you think its got any thing to do with this...??
[Link]