A BOMBING campaign by animal rights extremists appears to have been thwarted by the seizure of incendiary devices by police.

The devices and "associated materials" were discovered when police stopped and searched a car in Camp Hill, Northampton. A local man and one from London, both in their 30s, were arrested and were being questioned by detectives yesterday. The area was sealed off and the men's vehicle, a red Vauxhall Cavalier, is being subjected to forensic analysis.

Det Chief Supt Peter Barclay, head of Northamptonshire Police Crime Support Department, said: "This is a significant find related to animal rights activities. A team of officers and support staff will be engaged on the inquiry in the coming weeks.

"Experts from forensic science and other support organisations are working with us, and the devices and other materials we have found will be scrutinised in very fine detail." He said that no further details could be released for operational reasons.

Incendiary devices, which ignite with sufficient force to cause fires and small explosions, are viewed as valuable weapons by animal rights extremists.

Last month, Barry Horne, 45, of Northampton, was jailed for 18 years for arson attacks on stores across southern England. Detectives acting on a tip-off arrested him as he planted incendiaries in Bristol shops.

In 1996, David Callender was jailed for 10 years for plotting a nationwide firebomb campaign.

In July 1995, David Woolley, a hunt leader, and his son, Josh, six, were injured when a letter bomb exploded at their home. The incendiary device went off as Mr Woolley opened his mail at breakfast.

Police investigating a blaze at the AF Ensor abattoir in Cinderford, Glos, a month earlier also found more than 20 incendiary devices, some of which had failed to go off.