The fourth suspect in last week's twin attacks in Spain was released Thursday pending further investigation and placed under surveillance, the country's National Court said.

Salh El Karib, the manager of a store that lets people make calls abroad in Ripoll, a town in northern Catalonia where many of the alleged attackers came from, will have to show up at a local court every week and is banned from leaving Spain, the court said in a statement.

Salh El Karib, a 34-year-old Moroccan, is the second of four suspects to have been granted conditional release.

The two others -- Mohamed Houli Chemlal, 21, and Driss Oukabir, 28 -- were remanded in custody and charged with terror-related offences after being quizzed by a judge at Madrid's National Court, which deals with cases of extremism.

Authorities are still probing the vehicle attacks in Barcelona's busy Las Ramblas boulevard last Thursday and in the resort town of Cambrils several hours later.

Fifteen people died and more than 120 were injured.

According to a court document, credit cards in the name of Salh El Karib were used to buy plane tickets for Oukabir and Abdelbaki Es Satty, the imam believed to be the mastermind of the terror cell. He is now dead.

But the investigation found that the shop he manages sells plane tickets as part of its regular business offering, which means he did not necessarily play a part in the terror cell.

"There is no indication that the detainee had any relationship with the people allegedly involved in the terrorist organisation that is being investigated," the court document said.

Source: AFP