A terrified worker at a German cinema has revealed how he mistook a gunman for a film fan wearing a costume before he opened fire and took them hostage.

Guri Blakaj initially dismissed the masked man who stormed the Kinopolis cinema complex in Viernheim, Western Germany, at about 3pm on Thursday carrying a gun and ammunition belt.

He believed the man he saw standing 'by the popcorn stand' to be a customer wearing a costume, complete with the belt of cartridges draped across his shoulder.

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A gunman has been shot dead after opening fire inside a cinema in Western Germany

Heavily-armed police stand outside a cinema complex where an armed man has opened fire

Police surrounded the cinema complex after receiving a call at around 2.45pm

But then Blakaj, who was working the till at the time, realised it was 'something more serious'.

As his colleagues were told to lie down, Blakaj was ordered to close the doors to the cinema.

All the while, the gunman held his weapon to his head.

Blakaj, who was told to go and sit in his office after shutting the doors, said the man also shot at a colleague but didn't hit him.

'He seemed very confused, and was relatively young,' Blakaj said, adding he had asked if the man wanted money, to which he responded he didn't.

The assailant then went into one of the theatres. Blakaj, who said there were about six workers and 30 cinema-goers in the building, then heard shots fired. Other reports suggest there were about four shots fired in total.

Almir H., 16, said he was one of the hostages taken by the man in the cinema. He claimed he was locked in a toilet and said, in broken German: 'Lie down in here if you love your life.'

Police special forces later stormed the building and shot him the masked man.

Bild newspaper reported that a suicide vest and a hand grenade were found near the body of the dead man, although police have not confirmed this. Authorities have said, however, that the man was mentally disturbed and not linked with any terrorist group.

Video footage shows the moment heavily-armed police storm the cinema complex

Reports people were injured by tear gas have been dismissed by police, who say there were no other injuries.

The interior minister of the state of Hessen, Peter Beuth, announced the perpetrator's death in the state parliament in Wiesbaden.

He said: 'The police had an emergency call at 2:45pm [12:45 GMT]. The caller said there was a masked man... armed with a long gun. It is unclear whether it was a real gun.

'The caller heard four shots and said that the masked man appeared a little mentally unstable. Police special forces were called.'

Police spokesman Bernd Hochstaedter said that 'there are no indications at present of an Islamist background.'

Police received a call saying there was a 'masked man... armed with a long gun'

According to initial media reports, the man entered the cinema today at approximately 3pm, fired a shot in the air and barricaded himself inside

Elite SEK police commandos were helicoptered to the scene before storming the cinema

Video footage has emerged of a large group of heavily-armed police storming the cinema. They are shown creeping up against the wall before entering the building.

The motive for the attack is unclear - whether he is a 'lone wolf' terrorist or a deranged individual.

The incident has echos of the Aurora cinema mass shooting that occurred in Colorado in 2012.

Gunman James Holmes murdered 12 people and injured 70 others when he opened fire during a midnight showing of the film The Dark Night Rises.

Holmes entered the cinema wearing tactical clothing and set off tear gas and grenades into the audience.

He was arrested minutes later in his car parked outside the cinema.

On Thursday, Elite SEK police commandos were helicoptered to the scene in Germany and ambulances have ferried the injured to local hospitals.

The Kinopolis cinema complex is located in the town of Viernheim.

The German Ministry of Interior announced the gunman had been shot dead

A gunman has opened fire at the Kinopolis cinema complex in the town of Viernheim

The gunman barricaded himself inside the cinema (stock photo)