The Isis terror group is believed to have released a new propaganda video praising recent attacks in Spain.

At least 15 people died in vehicle and knife attacks in the towns of Barcelona and Cambrils on 17 and 18 August.

The three-minute-long footage, entitled the Conquest of Spain, is believed to have been released on the Telegram messaging app, often used by the militants to share their propaganda material.

The footage features a bearded man, believed to be an Isis militant from Spain, praising the attack. He claimed they were in revenge for the killing of Muslims at present time and during the Spanish inquisition (1478-1834).

"Jihad has no borders, make Jihad where you are. Allah will be pleased with you," the man says in Spanish.

"To Spanish Christians, never forget the Muslim blood split during Spanish Inquisition. We will avenge your killings and the killings you are doing against the Islamic State now," he continued.

"Al-Andalus [former Muslims territory in modern day Spain and Portugal] will go back to what it was, a Caliphate land."

The video also shows the coverage of the attacks by mainstream media. a masked man also appears in the footage and says: "Allah accepts the sacrifice of our brothers in Barcelona. Our war against you will continue until the end of the world."

The masked man then urges people to abandon Christianity or we "will never leave you in peace".

Isis praises Spain attacks
Video features a bearded man, believed to be an Isis militant from Spain, praising the attacks which, he claimed, were in revenge of the killing of Muslims at present time and during the Spanish inquisitionYouTube Screenshot

At least 14 people were killed during a van and knife attack in the popular tourist spot of Las Rabmlas, Barcelona, on 17 August.

Police idenitified Younes Abouyaaqoub, a 22-year-old Moroccan man, as the person who drove the van during the attack.

Abouyaaqoub, who was killed after a days-long manhunt in Spain, was also the alleged ringleader of a 12-strong cell that orchestrated a similar vehicle attack in Cambrils on the morning of 18 August. One person died in that attack.

Isis claimed responsibility for the attack via its news agency Amaq. However, such claims have often come in the aftermath of similar attacks across Europe, and are not always reliable.

Authorities said the cell, now dismantled, had been radicalised by Imam Abdelbaki Es Satty, who is believed to have died in an explosion at a house in Alcanar on 16 August.

Members of the cell were building explosive devices before the attack. Following the incident, they opted to use vehicles instead.

The only four surviving members of the cell were taken to court on 23 August.

Two of them, Mohamed Houli Chemlal and Driss Oukabir, were charged with murder, membership of a terror organisation and the possession of explosive. They are being held in prison without bail.

Another suspect, Mohammed Aalla, was released on bail due to weak evidence, while Salah el Karib is still being questions by the police.

Oukabir has always claimed he is innocent in spite of the fact that his documents were found in the vehicle used in the Barcelona attack.

The man, however, maintains that his younger brother – shot dead by police during the Cambrils attack – had stolen his documents to hire the vehicle.