BARCELONA, Spain (AFP) - Spanish police arrested 10 Pakistanis suspected of involvement in Islamic extremism during an operation in the northeastern region of Catalonia.
However, the sources said the arrests were not related to the March 11 attacks in Madrid that left nearly 200 people dead.
"An operation was launched against Islamic activists and several people were detained," a spokesman for Catalonia regional police said when contacted by telephone from the capital.
Judicial sources in Madrid said the suspects were arrested "for Islamic terrorism" and said all were of Pakistani origin.
Twenty suspects have been arrested in relations to the March 11 attacks. Most are Moroccans and none was a Pakistani national.
A police spokesman told AFP that the Pakistani suspects "could have financed radical organisations outside Spain`s borders."
Judicial sources said they were sifting through documents to determine "the contours and the methods pertaining to this collaboration."
Judicial sources in Madrid said police had not discovered any weapons or explosives but only documents including false identity papers as well as "books on (Al-Qaeda leader Osama) Bin Laden."
Five of the Pakistanis were detained in the northern Barcelona district of Trinitat Vella and five more in the central "Barrio chino" or Chinese district, where there is a concentration of Pakistanis.
Sixteen suspected Islamic radicals from North Africa were arrested in the Catalonia region of eastern Spain in January last year but released for lack of evidence three months later.
Four of them, all Algerians, were arrested once more and charged last March with belonging to a terrorist organisation, the Salafist Group for Preaching and Combat (GSPC), a sub-section of the Islamic Armed Group.