Spanish police identify remains of last terror cell suspect

"Youssef Aalla is the last corpse identified in the Alcanar explosion," Catalan regional police said, referring to an accidental blast at the jihadists' bomb factory on the eve of the August 17 assault in Barcelona.

"That is the last known member of the cell" whose remains had not been formally identified, they said.

The explosion also killed an imam, Abdelbaki Es Satty, who is believed to have radicalised the young men in the cell.

It was so strong that "the mushroom cloud that was generated was visible several kilometres (miles) around," according to court documents.

The blast forced the suspects to turn instead to using vehicles as weapons.

They ran down people in a crowded avenue in Barcelona on August 17, and in the nearby seaside town of Cambrils in the early hours of the following day. Fifteen people were killed and more than 120 injured.

Aalla is one of three brothers caught up in the case.

Said Aalla, 18 was shot dead by police in Cambrils as he and four others ran pedestrians down with a car.

Their older brother, Mohammed, 27, was detained initially by police but was granted conditional release on Tuesday as the judge deemed evidence against him too weak.

His Audi A3 was used in the Cambrils attack, but he has told the court that it was registered under his name for insurance purposes. The car, he said, was used by his brother, Said.