dpa - Spain could sue 13 agents of the US Central Intelligence Agency (CIA) travelling on a plane which is thought to have transported terrorist suspects and which made stopovers in Palma de Majorca, the daily El Pais reported Wednesday.

An association of lawyers and a group of professionals based in Majorca have sought an indictment for torture at the National Court.

If prosecutors and the judge agree, the tribunal could indict the US agents and eventually seek their extradition, sparking diplomatic tension with the US.

The B-737 plane made a 12-day trip, with Washington as the point of departure and arrival, with 12 stopovers, including two in Palma de Majorca between 22 and 26 January, 2004.

During some legs of its trip, the plane is believed to have illegally transported Khaled al-Masri, a German citizen who was taken from Macedonia to Afghanistan, and Ethiopian Binyam Mohammed, who was flown from Morocco to Afghanistan.

At least five of the CIA agents in question had diplomatic passports, according to El Pais. The US refuses to submit its secret agents or military officers to the authority of foreign courts.