Telegraph website updated
(finally). Contains this quote from the police:
A spokeswoman for Hertfordshire Police said: "Police and other emergency services are attending the area of Buncefield oil depot near Hemel Hempstead following reports of an explosion just after 6am.
"There is nothing to suggest at this stage that this is anything but an accident, but we are keeping an open mind. Contrary to rumours in circulation, there is also nothing to suggest that a plane was involved in this accident."