A man wielding a large kitchen knife killed one and wounded four others after storming into a supermarket in the German city of Hamburg.

The attacker is reported to have screamed 'Allahu Akbar' before running into the Edeka shop where he stabbed one person and slashed at four others while trying to flee.

He was pursued by passers-by who wrestled him to the ground and called the police, who later arrested him.

One officer said there was 'no valid information on the motive of the attacker' who has yet to be identified.

German daily Bild published a photo of the attacker in the back of a police car with a white, blood-soaked bag over his head.

Scroll down for video

A knife-wielding man has killed one and injured several others after going on a stabbing rampage through a German supermarket this afternoon

Heavily armed police have locked the area down and an air ambulance helicopter was seen on the road outside

Police investigators work at the crime scene after a knife attack in a supermarket in Hamburg, Germany

Security forces and ambulances descended on the scene after the a knife attack in a supermarket in Hamburg

A female witness claimed the assailant ran out of the shop with his hands in the air while yelling 'Allahu Akbar', though police have not confirmed this.

The woman, who was queuing for the till when the rampage began told NTV she was 'afraid of dying'.

'The man has suddenly struck out on customers, there was one dead and several injured,' another witness told Bild.

Hamburg police confirmed he was the only attacker, tweeting: 'The first reports about a possible motive of a robbery have not been confirmed.'

Police have blocked off the lively and diverse high street in the north-east port city which hosted the G20 summit of world leaders in early July.

Anti-terror police have also been deployed to the scene while homicide investigators scour the area for evidence and clues.

A police officer walks past crime scene after a knife attack in a supermarket in Hamburg, Germany

There was no information immediately available about the dead person but police disclosed one of the four injured was in a serious condition.

A major manhunt was executed and 30 minutes later, photos emerged of a suspect in the back of a police car.

He is understood to have suffered minor injuries as he was being held by bystanders.

Germany has been on high alert about the threat of a jihadist attack, especially since last December's truck rampage through a Berlin Christmas market that killed 12 people.

The Islamic State group claimed responsibility for the carnage in which a Tunisian rejected asylum seeker and ex-convict, Anis Amri, 24, ploughed the stolen truck through a crowd.

It was Germany's deadliest attack by an Islamist militant, but not the first.

Heavily armed officers have locked the area down and police helicopters have been seen above the crime scene

A motive for the attack, which left one dead and four others injured, has not been established

Hamburg police (forensic team pictured) said on Twitter that there was only one attacker

Armed police have been pictured on the scene having cordoned off the area. A fire fighter was pictured accompanying an elderly woman from the scene

The attacker ran into an Edeka shop in the northern city of Hamburg before knifing customers and going on the run

Hamburg police said on Twitter that there was only one attacker and that the motive for the incident in Hamburg's Barmbek district wasn't immediately clear

Hamburg police said on Twitter that the motive for the incident in Hamburg's Barmbek district wasn't immediately clear

In 2016, the IS group also claimed a suicide bomb attack in the southern city of Ansbach which wounded 15 victims, and an Afghan man's axe rampage on a train in Bavaria that hurt five, before the perpetrator was shot dead by police.

Public fears about more extremist violence have grown amid Germany's mass influx of refugees and migrants, mostly from Syria, Iraq, Afghanistan as well as several African countries.

More than one million asylum seekers have arrived in Germany since Chancellor Angela Merkel opened the country's borders in 2015.

Germany's domestic intelligence service estimates there are about 10,000 radical Islamists in the country, including 1,600 who are considered potentially violent.

In one case of a homegrown attacker, a German teenager identified as 16-year-old Safia S. was in January sentenced to six years of juvenile detention for stabbing a police officer in 2016 'to support the Islamic State group'.

Lockdown: Heavily armed police stand outside a Lidl supermarket in the shopping area

Police said that 'initial reports about robbery as a possible motive so far have not been confirmed'

Police swooped to arrest a suspect after witnesses followed the attacker and called raised the alarm

Authorities were also investigating an IS claim of the stabbing death of a teenage boy in Hamburg last October.

The 16-year-old boy was fatally wounded in the knife assault on the banks of the Alster river but a 15-year-old girl who was with him escaped unharmed after the attacker shoved her into the water.

Germany is a target for jihadist groups, particularly because of its reconnaissance and refuelling missions to support the coalition fighting IS in Iraq and Syria, and because it has deployed troops in Afghanistan since 2001.