Pakistan link to terror arrests as Gordon Brown defends operation.

(From Guardian Unlimited)

Suspects being questioned after one of the biggest anti-terror operations since the July 7 attacks exploited lax student visa regulations to enter the UK from Pakistan, Whitehall sources said today.

As police carried out searches in -Liverpool, Manchester and Clitheroe, Lancashire, following the terror raids on Wednesday, the Home Office said student visa checks had been tightened in the last fortnight because of widespread abuses of the system.

There are concerns inside government and security services that the 11 Pakistani nationals being held in the north of England could have gained entry on student visas in order to form a sleeper cell.

The terror operation which led to the arrest of the men, along with one Briton who is said to have roots in the same tribal area they came from, was rushed forward after the country's top anti-terror …