SABOTEURS buried "bed of nail" booby traps in picturesque East Lancashire woodland in an attempt to spike the tyres of mountain bikes.

But now they have been warned: "Somebody could be seriously injured."

The alarm was raised by a walker from Broken Stone Road, Livesey, Blackburn, when a two-inch nail penetrated his boot in nearby Tockholes on Easter Monday.

The man, who does not want to be named, suffered slight foot injuries after he accidentally trod on a trap.

North West Water, who own the land, sent out a ranger to investigate the complaint and found 20 planks of wood, dotted with sharp iron nails, sunk into earth along a section of footpath below Fine Peters in Roddlesworth Woods.

A series of discs, scrawled with the warning 'no bikes', were discovered hammered onto trees in the same area yesterday afternoon by PC Sue Large (pictured with the nail traps), the rural beat officer for Belmont and Tockholes, and Ian Walker, a North West Water woodland project officer. Two more traps were dug up close-by and wooden logs had been positioned to direct mountain bikers onto the nails.

Mr Walker said: "We believe the bed of nails were deliberately planted to stop mountain bikers using the footpaths in the wood.

"There are about 15 to 20 miles of footpath in the area. We are carrying out a search and are warning people visiting the wood to be careful in case there are any traps left."

The discovery has also prompted a police investigation.

Inspector Stephen Haworth, of Blackburn police, said: "The person or people responsible for planting these traps could be facing wounding with intent charges. They would be looking at a custodial sentence up to life imprisonment.

"It has obviously been a well planned operation. What the offenders may not have realised is the wider implications.

"They have not only risked causing damage to mountain bikes but also serious injury to people and animals."

PC Large added: "Luckily the walker who reported the problem was not badly hurt. We have had to temporarily close the section of footpath.

"The problem has been made worse by the heavy rainfall. The nail traps are well hidden and we will probably have to draft in metal detectors to find any that remain."

Anybody with information is asked to call Darwen police on 01254 701777.