The Islamic State (ISIS) has threatened to carry attacks on the West "worse than 9/11 and last year's Paris massacre'' for a historical reason: To avenge Muslims who were expelled by Spain in Andalusia 500 years ago.

The warnings were contained in a new video released Saturday by the barbaric Islamic group.

The video, believed to have been filmed in Nineveh, shows a masked white man standing in the rubble of a building impacted by a military strike. He threatens to carry out atrocities on Westerners that will "make them forget September 11" attacks against the U.S. or the Paris massacre in November,'' Christian News reported.

The man reportedly shows his wrath towards Spain, which he says will "pay dearly'' for having crushed Muslim rule in ancient Andalusia, the southern Spanish region where the Moors ruled from 711 AD to 1492.

According to the Daily Mail, the man speaks "Cordoba and Toledo'' and says "the ancient land of Andalusia is Muslim and has not been forgotten."

Muslims had ruled in Spain for a time until they were chased out by Roman Catholic armies during the Spanish Inquisition. Many Spanish Jews who refused to convert to Roman Catholicism were expelled as well.

The Encyclopedia Britannica outlines that "[King] Ferdinand and [Queen] Isabella issued an edict on March 31, 1492, giving Spanish Jews the choice of exile or baptism; as a result, more than 160,000 Jews were expelled from Spain."

In 1502, Cardinal Jimenez de Cisneros issued an order to rid Granada of Islamic rule. The region thus became the last Muslim territory to fall in Spain. "Muslims in Valencia and Aragon were subjected to forced conversion in 1526, and Islam was subsequently banned in Spain," Britannica says.

The long-haired masked gunman also brands the U.S.-led coalition fighting ISIS in Syria and Iraq "imbecile miscreants" who will not be able to defeat the terrorist organisation.

The eight-minute propaganda production ends with the execution of five prisoners who are shot in the head by ISIS fighters. The men are dressed in orange jumpsuits and forced to kneel in the rubble, Christian News said.

In an earlier report published in an Arab language newspaper, al-Naba, the same long-haired masked man was described as having threatened an attack on Britain so horrific it will "turn children's hair white.''

The French-speaking man warned that U.K. will suffer "the lion's share'' of the slaughter it intends to do in Europe.