HEMEL HEMPSTEAD, England (AP) – Explosions ripped through a fuel depot north of London yesterday, injuring dozens of people, blowing doors off nearby homes and sending balls of fire and clouds of black smoke into the sky.

Police said the blasts appeared to be accidental, though just four days ago an al-Qaeda videotape appeared on the Internet calling for attacks on facilities carrying oil that has been stolen from Muslims in the Middle East.

The powerful explosions, felt throughout a large swath of southeast England, also rattled nerves in a country still jittery over a terrorist attack on London’s subway and bus system in July that killed 52 people and the four suicide bombers.

“Around 6:00 am, as we were sleeping, there was a mighty explosion – a thunderclap that woke me up,” said Neil Spencer, 42, who lives about 1 1/2 kilometres (three-quarters of a mile) from the Buncefield terminal. “It was fireball after fireball – truly amazing.”

Photographer Haris Luther, 57, who awoke to find the blast had destroyed the front door of his home, said: “I thought the house had been hit by lightning. It sounded like an earthquake.”

Most of the 43 people injured were treated and released after suffering cuts and bruises from the flying glass of broken windows in Hertfordshire county, about 40 kilometres (25 miles) north of London. But at least two men were hospitalised, including a plant worker in serious condition, said Howard Bortkett-Jones, medical director of the two local hospitals.

Noxious fumes from the fire, which left some people coughing, also affected the large squads of police who sealed off the area and evacuated nearly 300 people to a bowling alley being used as a temporary shelter. About 25 policemen were examined by doctors for problems such as chest tightness or shortness of breath, Bortkett-Jones said.

Several explosions occurred at Buncefield terminal, which stores 16 million litres (4 million US gallons) of gasolene, diesel, kerosene and aviation fuel, and officials warned that more could occur as it would take days to extinguish the inferno.

“(It’s) the largest incident of this kind in peacetime Europe,” said Roy Wilshire, the county’s chief fire officer. He did not elaborate.

On Wednesday, a videotape by al-Qaeda’s deputy leader, Ayman al-Zawahri, was shown on the Internet calling for attacks against Gulf oil facilities. The video had first been released on September 19 and shown on Al-Jazeera TV.

“I call on the holy warriors to concentrate their campaigns on the stolen oil of the Muslims, most of the revenues of which go to the enemies of Islam,” said al-Zawahri, the Egyptian deputy of al-Qaeda leader Osama bin Laden. “The enemies of Islam are exploiting such vital resources with incomparable greed, and we have to stop that theft with all we can and save this fortune for the nation of Islam.”

The cause of yesterday’s disaster was not immediately known, said Total SA, the French oil company that operates Buncefield in a joint venture with Texaco. The British subsidiary, Total UK, said in a statement it was in contact with police and security forces.

Buncefield is the fifth largest of some 50 major oil storage facilities in Britain. The Total/Texaco reserves there account for about five per cent of the country’s oil supply.

BP also has a storage facility at the site, which was not damaged in the blast.

Firefighters planned to use foam to stop the blaze spreading across the 450-metre by 850-metre (500-yard by 900-yard) depot and adjacent industrial park. The 20 blazing tanks were being allowed to burn themselves out, while about 100 firefighters and 100 police officers – some wearing face masks – stood watch at the site.