Three suspected al-Qaeda members with enough explosives "to blow up a bus" were arrested in southern Spain on Thursday amid fears they were on the verge of launching an attack on Gibraltar or the European mainland.

Two were detained on a bus bound for France, while the third was seized in a flat in La Linea de Concepcion, in the southern province of Andalucia.

Alleged to be a "facilitator for al-Qaeda", the third man is believed to be a Turk who worked in the construction business in Gibraltar for several years.

The three men had been under police surveillance for some time and Spanish police sources said they had been seen in recent weeks using a motor-powered paraglider around Gibraltar, where Britain has a military base, leading to speculation that they may have been planning an airborne attack.

All three reportedly received training in military camps in Afghanistan and Pakistan before basing themselves in Spain. One was alleged to be an expert in explosives and poisons.

"There is a clear indication that those arrested could have been planning an attack in Spain and/or [elsewhere] in Europe," Jorge Fernandez Diaz, the Spanish Interior Minister, told a news conference.

"These are extremely dangerous people. This is one of the biggest investigations which has been carried out up until now against the al-Qaeda terrorist group at an international level."

Two of the suspects, of Russian nationality and reportedly of Chechen origin, were arrested in the early hours of Wednesday at a service station in Ciudad Real, 125 miles south of Madrid. One of them had "used uncommon strength to resist arrest, using the military training he received, and special forces had to intervene," said Mr Fernandez.

The Turkish suspect was arrested later at his home in La Linea where police reportedly seized explosives as well as computers, manuals for flying light
aircraft and remote controlled aircraft. Last night he was identified locally as Cengiz Yalcin, who worked as a site manager at a building firm on Gibraltar, crossing the border each day from his home.

An acquaintance in the construction industry recognised Mr Yalcin from photographs released by Spain's interior ministry of the three suspects.

"I saw his photo flash up on the news and immediately recognised him as a site manager I have met on numerous occasions," said the industry worker, who did not wish to be named. Mr Yalcin is named as site manager on the website of Profield Contractors Ltd, one of the larger building firms on Gibraltar and one that has secured several government contracts.

An employee at the firm confirmed that Mr Yalcin was the man arrested but declined to comment further.

It is understood that he has worked for the firm for at least three years. Fellow workers in the industry believe he previously worked for another firm that had secured contracts with Britain's Ministry of Defence, but that could not be confirmed last night.

Photographs of the three suspects were released by the interior ministry but they were identified only by their initials: C.Y. for the Turk and A.A.A. and M.A. for the other two.

Gibraltar's government sought to reassure the public that there was no immediate threat of attack, but security at the border had been stepped up and on Wednesday evening every vehicle was stopped at the frontier for document checks, causing lengthy crossing delays.

The authorities declined to comment on reports that the suspects had links to Pakistan's Lashkar-e-Taiba, the group behind the November 2008 attack on Mumbai that killed 166 people.

Last month, two Spanish citizens were arrested in Melilla, a Spanish enclave in North Africa, on suspicion of terrorism.

In March, Spanish police arrested a Saudi citizen described as "the librarian" of al-Qaeda, in charge of its propaganda and recruitment activities.----

Source: http://www.telegraph.co.uk/news/worldnews/al-qaeda/9448028/Al-Qaeda-men-may-have-targeted-Gibraltar.html