Drivers on the M40 are again facing delays after police resumed searching nearby areas in an anti-terrorism operation.

The eastbound inside lane and the hard shoulder have been closed between junctions four and three, near High Wycombe, and will stay shut between 10am and 6pm until Thursday evening.

Thames Valley Police said the move was part of an "ongoing investigation" and advised drivers to avoid the road if possible.

It comes after similar searches were conducted by explosives experts on the same stretch of road on September 14 after "suspicious items" were found.

Scotland Yard refused to confirm reports then that the items being tested by forensics officers were bottles of liquid that bubbled and smoked when poured on the ground.

The spokesman said that he could not comment on claims that two 13-year-old schoolboys made the discovery.

He said: "All I can say is that the items were found by a member of the public."

The area under investigation is close to Booker Common, which has been searched by officers probing an alleged terror plot to blow up transatlantic passenger jets.

Anti-terror officers searched another area of woodland, known as King's Wood, on the other side of High Wycombe in connection with that investigation.

An address in High Wycombe was also raided during the inquiry into the alleged airliner bomb plot, codenamed Overt.