Gunman screaming 'Allahu Akbar' opens fire in Spanish supermarket while wearing 'suicide vest' filled with gasoline and gunpowder

A gunman has opened fire in a Spanish supermarket shouting "Allahu Akbar".

The attacker, who was reportedly carrying gasoline and gunpowder, walked into the Mercadona shop in the As Lagoas region of the northwestern region Ourense, before opening firing shots into the air, Daily Mail reports.

The attacker walked into the Mercadona shop, As Lagoas, before opening fire. Photo / Twitter

Several shoppers were inside the supermarket when the man entered and fired several shots into the air, causing emergency services to swoop in on the building.

According to police sources, the young man has psychological problems and lives next-door to the shop.

The incident, which happened at around 2pm (CET), did not result in any injuries but left many extremely shaken.

One employee confirmed that he had shouted the Arabic phrase for "God is great" before he began shooting.

The incident, which happened at around 2pm, did not result in any injuries but left many extremely shaken. Photo / Twitter

Witnesses told how they suddenly heard screams and shots before nearby officers screamed at them to get away.

According to Spanish media outlet La Region, police officer Carlos Perez, 38, revealed the gunman fired at him and he had to wait for backup.

He and his colleagues were able to detain him after he ran out of ammunition, and later they emerged with a makeshift vest.

Photos from after the incident show wine and broken glass strewn all over the shop floor.

He was reportedly carrying gasoline and gunpowder, and was later detained after a struggle ensued. Photo / Twitter