Firefighters tackling the massive blaze at the Buncefield oil depot near London were tonight forced to halt attempts to douse the fire amid fears of a fresh explosion.
The fire chief in charge of the operation at the oil depot near Hemel Hempstead, Hertfordshire, described the withdrawal as a "temporary setback". Roy Wilsher, chief fire officer of Hertfordshire Fire Service, said he hoped that firefighters would still be able to extinguish the blaze by daybreak tomorrow.
More than 150 firefighters have been battling to douse the blaze - which began following a series of explosions at 6am on Sunday - since dawn today.
Mr Wilsher said senior officers decided to withdraw after becoming concerned that firefighters would be killed.
He said experts were worried that a fuel tank which had so far remained intact might explode. He added that firefighters needed to be "100 per cent certain" what was in the tank before continuing to battle the blaze.
Mr Wilsher stopped short of saying that firefighters were forced to flee for their lives but he said the prospect of another massive explosion had "concentrated their minds".
He said firefighters had thought that they were safe to enter the blazing depot because they had been able to keep the tank - labelled "tank seven" - cooled and were confident that it would not explode.
The top of a nearby tank - "tank five" - had caught fire but firefighters were able to extinguish that blaze.
Problems arose when "tank five" unexpectedly ruptured and blew up at around 3pm. Firefighters had withdrawn when "tank five" ruptured. And senior officers decided not to re-enter the site fearing that the heat generated by the fire in "tank five" would cause "tank seven" to explode.
PA