TWO men sparked a major terrorism alert when they had large numbers of gas canisters delivered to their illegal cannabis farm.

Police pounced on the industrial estate in Birley Street, Blackburn, after a tip off in the wake of a foiled car bombing in London's West End and the attack on Glasgow Airport last June.

But instead of making bombs, Ifzal Rafiq and Mohammed Tahir were using the fuel to help grow high potency skunk cannabis.

A total of 175 plants were found in one room, 25 "mother plants" in another area, plus 62 cuttings which they were attempting to grow.

The 8,000 sq ft unit was being rented on a three-year lease at a cost of £20,000-a-year and the men were detained when they gave false details to the police at the scene.

Rafiq, 22, and Tahir, 30, both of Keighley, pleaded guilty to producing cannabis between June 1 2006 and July 3 2007. Rafiq was jailed for two years and Tahir for 28 months.

Preston Crown Court heard that £8,000 to £10,000 of work was carried out inside the premises, including pits being dug into the solid floor and also electrical works.

The unit came to the notice of the police after several orders and deliveries were made for propane gas canisters.

Mr Roger Baldwin, prosecuting, said that on Friday, June 29, there had been a foiled terrorist bombing attempt, involving a car containing propane gas in London's West End.

The following day there was an attack on Glasgow Airport.

Mr Baldwin said that the attacks caused the owner of the gas company to be rather more worried about what was happening at Birley Street.

On June 30 the man rang Lancashire Police to pass on his suspicions.

Two plain clothes officers were in the area when a delivery took place on July 3.

The defendants gave false names and details and ended up arrested under Section 41 of the Terrorism Act.

Mr Baldwin said that what was found related to a very different crime - a sophisticated and well planned cannabis factory capable of cultivating more than 900 plants.

Miss Charlotte Worsley, for Rafiq, a building society worker, said he came from a law-abiding family who were devastated by his behaviour.

Mr Abraham Verghese, defending Tahir, said he had given into the temptation of making money.