Explosives experts were analysing the sized materials determine if some of it was triacetone triperoxide, or TATP.

Poice laboratories had not arrived at the final conclusion, the spokesman said.

TATP is an unstable explosive compound used by Islamic militants in the deadly 2005 London transit bombings, by Palestinian suicide bombers and Richard Reid, a British national who attempted to detonate a shoe bomb on a US-bound aircraft.

After the Barcelona arrests, interior minister Alfredo Perez Rubalcaba said the suspects appeared to form part of a well-organised Islamic militant group.

Leading newspaper El Mundo said the arrests could have been linked to the arrival in Barcelona of an unnamed suspect known by several intelligence agencies.

Joan Saura, the interior ministry’s representative in Catalonia, told regional lawmakers at Barcelona’s Parliament yesterday that despite the arrests he did not view Barcelona as “a city at risk”.

Europe’s worst Islamic-linked terror attack took place in Madrid on March 11, 2004, when bombs went off in railway carriages during the morning rush hour near the city’s Atocha station. The attack killed 191 people and injured more than 1,800. Twenty-one people have been convicted of involvement in that attack.

The attacks were claimed by Muslim militants, who said they had acted on behalf of Al-Qaida to avenge the presence of Spanish troops in Iraq, but Spain’s courts found no evidence that Al-Qaida ordered, knew about or financed the attacks. AP

New Delhi: India has sought details of two of its citizens arrested in Barcelona, for allegedly plotting a terror attack in that country, official sources here said today.

The sources said India would take necessary action after receiving details from the Spanish government. The question of extending legal assistance to the two would arise only after ascertaining the charges against them.

If there was ground for suspicion against the two, Indian security agencies might initiate its own investigations, the officials said. — UNI