Spanish police have arrested three Moroccans suspected of helping finance last year’s train bombings in Madrid and providing weapons today.

A judge today jailed two Moroccan brothers on provisional charges of collaborating with a terrorist group in connection with the deadly Madrid train bombings last year, but ordered their parents to be released.

Police tightened security in Madrid today after an Islamic group, which claimed responsibility for the March 11 train bombings in the capital, threatened to turn Spain into “an inferno”.

The ringleader of last month’s Madrid terror attack was among four suicide bombers who blew themselves up as police prepared to storm their apartment, Spain’s interior minister said today.