Islamic radicals may have been plotting attacks in Barcelona, Spain's Interior Minister Alfredo Perez Rubalcaba said yesterday, after police found bomb-making materials and arrested 14 South Asians. Rubalcaba told a news conference that civil guard police found explosives and other equipment during raids on five addresses in Spain's second city and arrested 12 Pakistanis and two Indians after receiving information from its own and other European intelligence agencies.

Spain suffered Europe's deadliest Islamist attack in March 2004 when four Madrid trains were bombed, killing 191 commuters and wounding a further 1,800.

Rubalcaba said yesterday's raids were distinct from a number of operations against Islamic militants in recent years which largely targeted groups that sought to finance radical groups or recruit members to fight.

"Here we are looking at something different: a well-organised group who were going beyond ideological radicalism to acquiring materials to make explosives and therefore eventually to carry out violent attacks," he said.

Spain's Interior Ministry regards Islamic militants, rather than Basque separatists ETA, as Spain's greatest security threat and has significantly beefed up surveillance of mosques and employed more Arabic translators in the last four years.

Rubalcaba said the group, which had stockpiled bomb-making materials including timers, ball-bearings and batteries, had been ready to act. Computers were also seized during the raid in the old district of Raval just after midnight. The operation is continuing and Spain remains on a high level of alert against possible attacks, the minister said.