LONDON, Nov 12 - A large blaze destroyed an empty warehouse near the site of the London 2012 Olympics on Monday before more than 70 fire fighters brought it under control, the London fire brigade said.

Firefighters extinguish a fire at a warehouse on an industrial estate in the Stratford area of east London, November 12, 2007. A huge blaze at a warehouse sent black smoke pouring over east London on Monday but there were no reports of casualties and police ruled out a terrorist attack. [Agencies]

No one was hurt but the fire produced a thick, dark cloud of smoke that filled the sky over east London.

It was not immediately clear what caused the blaze but police ruled out terrorist activity.

"Not at all," said a police spokesman. "It's a fire -- a very large fire."

Fifteen fire engines and 75 firemen battled for nearly four hours to bring the flames under control.

Witnesses said the fire broke out as the warehouse was being demolished as part of preparations for the 2012 Olympics. It sent flames 40 to 50 feet (12 to 15 metres) into the air and a towering column of smoke could be seen for miles.

Printer Paul Izzet, 43, works nearby and was 50 yards from the site when the blaze started.

"After 10 minutes, it was like having your face six inches from a coal fire, it was that hot," he told Reuters. "It was really beginning to warm up."

In July 2005, suicide bombers killed 52 people on London's transport system and there have been several attempted attacks since then, keeping Londoners' nerves on edge.