A suspected member of the terror cell that killed 14 people in Catalonia last week has been threatened with his life by fellow inmates at a Spanish prison, according to local reports.

Driss Oukabir, 28, has been warned he will have his throat cut by other prisoners at Soto del Real jail in Madrid where he is being held in an isolated cell following his arrest in the aftermath of the Las Ramblas van attack.

Other detainees lent out their windows and shouted: "We are going to slit your throat when you go out to the patio," according to security sources that spoke with El Pais.

Others wailed, "F**king terrorist", at the Moroccan-born man whose brother was among the five killed in Cambrils in a suspected terror attack hours after the Barcelona massacre.

Oukabir told a judge on Tuesday that he had rented the van that was used in the Las Ramblas attack but that he understood it was going to be used for a house removal.

He was not in Barcelona at the time of the atrocity. He handed himself into police in his home town of Ripoll when his photograph was circulated around the world in the aftermath of the attack.

He was charged with murder, membership of a terror organisation and the possession of explosives, according to Sky News.

He is one of four surviving members of the alleged cell that had masterminded large scale attacks on tourist attractions in Barcelona only to be thwarted by an accident at their apparent bomb factory 60 miles away in Alcanar.

The others are:

  • Mohamed Houli Chemlal – also charged with murder, membership of a terror organisation and the possession of explosives;
  • Salah el Karib – kept in detention while he is investigated further; and
  • Mohammed Aalla – released on bail because the evidence against him is weak.
Driss Oukabir
Driss Oukabir is led from his isolated cell to appear in court on 22 August Getty

The alleged mastermind of the attack is Imam Abdelbaki Es Satty who died accidentally on 16 August in a property containing more than 100 gas canisters and TATP, an explosive nicknamed "Mother of Satan" used in the 2005 London bombings and by Richard Reid, the 2001 shoe bomber.

A handwritten pledge of allegiance to Isis has been found in the debris of explosion, which killed two others.

This morning (24 August) Dutch police arrested a 22-year-old man in Rotterdam after a terror warning from the Spanish police. The suspect is a Dutch national who lived with his parents in Zevenbergen. It is not known if the tip-off was related to the Barcelona investigation.