The latest terrorist threat....

How about hijacking fuel trucks and driving them into gas stations?

Police admitted last night that they are no nearer to finding a mastermind behind the July 7 bombings as Scotland Yard faced a new threat from terrorists driving hijacked fuel tankers into petrol stations.

A focus for the investigation will be to trace any video evidence recorded by the four bombers admitting the attacks, as other British suicide bombers have done in the past.

Counter-terrorism officers want to pour more manpower into investigating the July 7 atrocity but will now have to concentrate on the weekend warning from the US Department of Homeland Security, which said that terrorists plan to strike within the next month in Britain and in New York, Chicago and Los Angeles.

Scotland Yard’s priority remains preventing another attack but it will draft more officers into hunting the support network behind the 7/7 attacks, which killed 56 people.

Police do not know where the four bombers spent the night before the attack and senior officers do not believe that they acted alone.

One senior source said: “The background of these four does not suggest that they could have done everything themselves. Someone had to train them in building a sophisticated set of bombs and all sorts of other logistical support.”

Sir Ian Blair, the Metropolitan Police Commissioner, has conceded that tracing any third terrorist cell is proving difficult as there is no intelligence on those involved in the attacks.

Scotland Yard dare not relax the London lockdown with reports that another terrorist cell is in place. Sir Ian said at the weekend: “The fact that we had two attacks makes the possibility of a third attack more likely, not less likely.”

US agents would not say how they had discovered details of the plot to hijack fuel tankers, a favoured terrorist tactic in the Middle East.