A group of Islamist extremists in Frankfurt was planning an attack in Germany, according to a would-be suicide bomber captured by police in Spain, Spanish newspaper El Pais reported today.

The Frankfurt cell was one of several in European cities with orders to attack targets in Spain, France, Portugal, Germany and Britain, according to the would-be attacker turned police informant, El Pais reported.

The report did not make clear whether the German cell was to attack Frankfurt or another city.

Testimony from the same informant, who was captured after he arrived in Barcelona on January 16, led to the arrest of 14 South Asians yesterday in Barcelona after he told police an Islamist extremist cell planned to attack the city's metro and other targets in Europe, El Pais reported, quoting Spanish police.

The informant told police that leaders of the Barcelona cell told him to travel to Frankfurt to meet up with a group planning an attack, El Pais reported.

"They told him, initially, he was going to travel to Frankfurt," El Pais reported. "The informant thought he would travel to Germany to meet up with the group that was planning an attack there."

The plan changed and another member of the Barcelona cell, Akeel Abassi, was sent to Frankfurt on January 18 with orders to work alone, the informant told police.

Mr Abassi is being hunted by police, along with two other possible suicide bombers, El Pais reported.