MADRID: Spain's Civil Guard has arrested a fourth suspected Islamic militant in the northeastern region of Catalonia, believed to be linked to others accused of trying to buy explosives last week, local media reported on Saturday. A Civil Guard spokesman declined to comment and Interior Ministry officials were not available. Three Moroccans were detained in the Barcelona area on Wednesday suspected of links to "international Islamist terrorism networks", the Interior Ministry said. The latest arrest, part of a crackdown on suspected militants in Spain in the wake of the March 11 train bombings, took place on Friday, state radio reported. The suspect's flat was searched and several documents seized by police before he was transferred to Madrid, where he will be questioned by a judge in the coming days, reports said.