AN ANNUAL motorcycle rally organised by the Hell's Angels at a disused airfield in the Warwickshire countryside has been threatened with explosives attacks by rival biker gangs, according to police intelligence.

The Bulldog Bash which is expected to attract at least 20,000 motorcycle enthusiasts and generate around pounds 500,000 for the Hell's Angels began yesterday under the distant watch of armed police.

Officers outside the site carried out random searches as bikers arrived for the start of a four-day rally, which has been drawn into a feud between the Hell's Angels and their rivals, the Outcasts and the Outlaws.

The feud, which was revealed last month in The Independent, has been linked to fatal stabbings and a series of shootings and attempted arsons and bombings during the past year.

Warwickshire police fear the Bulldog Bash - which for 11 years has been held without serious problems in the village of Long Marston, near Stratford- upon-Avon - will become the next battleground in the biker war.

Deputy Chief Constable Mike Brewer said: "The National Criminal Intelligence Service issued a warning some three weeks ago to all forces referring to possible armed conflict. Their warning referred specifically to automatic weapons and explosives."

The police have no powers to stop the event because it is held on private property and the Hell's Angels make their own security arrangements.

Mr Brewer said two meetings had been held with the Hell's Angels All England chapter, at which requests for a cancellation had been made but declined.

Yesterday at the airfield there was little indication of the threat of armed conflict. Onsite security was handled by 200 Hell's Angels and their "helpers" - mountains of leather, hair and blue-green tattoos who stalked the perimeter. Nearly every biker and almost every vehicle entering the airfield was searched.

The event is scheduled to run until Sunday and includes a live performance by veteran rock band The Stranglers, a rave tent and various biker-related events.

Yesterday a village of tents was being established and stalls were set up to sell beer, hot dogs and vegetarian food for the New Age biker.

The roar of bikes, quads, trikes and one-cylinder Harley Davidsons underpinned every activity.

In an interview with BBC radio, Hell's Angels spokesman Maz Harris said his gang was co-operating with police after the explosives warning.

"It does sound fairly alarming and I have been to several talks with Warwickshire police," he said. "Frankly I think it's a red herring. It's ever so easy to phone up and make bomb threats in order to cancel an event."

He said there was no question of stopping the event but extra safety precautions were being taken.

According to Mr Harris, the biker feud is being exaggerated. "It seems to me that people inside the motorcycle community know more than [police] do about what could happen. There are always fights going on between rival bikers."

Later yesterday, Mr Harris, 49, who has a PhD in motorcycle culture, told The Independent : "There are people you get on with in life and there are people you don't but it doesn't mean you have to blow them up.

"This, for Angels and other bikers, is our annual holiday. You rub along as best you can."

Some bikers at the Bulldog Bash attributed the explosives warnings to a rogue e-mail from a dissident biker group.

But Warwickshire police said they were taking the threats "very seriously".

Meanwhile Jack Straw, the Home Secretary, has been urged by sections of the motorcycle industry to make the Hell's Angels a proscribed organisation because police have linked the gang with criminal activity.