Barcelona - Spanish police Tuesday detained 13 people on charges including the falsification of passports and drug trafficking, police said.

Police were investigating whether the detainees had links with the terrorist network al-Qaeda.

Eleven of the suspects were held in Barcelona and 2 in Valencia in the east of the country. They included 11 Pakistanis, an Indian and a Nigerian national.

The detainees were suspected of stealing passports which were sent to Thailand for falsification before being handed over to criminal rings in France, Belgium, Switzerland, Britain and Germany.

Police searched several addresses, seizing dozens of passports and falsification equipment. (dpa)