THIS is the incredible moment a hero tourist wrestles and pins the Amsterdam knifeman who stabbed five in a “random” attack.

The assailant knifed a woman in the back and slashed two American tourists, amongst others, in the heart of the Dutch capital.

After several minutes of violence on Thursday, a heroic intervention from a passerby put an end to the horror.

The knifeman was held in a citizen’s arrest until being detained by police shortly after 3:30pm local time.

And now, incredible footage has emerged of the moment the civilian overpowered the thug.

The clip shows the hero kneeling on top of the attacker who is pinned face-down on the tiled square.

His hands are pulled behind his back, held fast by the brave man.

A crowd of shocked civilians encircles the pair, but the hero has the situation comfortably under control.

Police later swooped on the assailant and took him to hospital for treatment to a leg wound.

They confirmed the saviour was a tourist in the city, but did not give his nationality.

The cops described his intervention as “heroic”.

They explained he had stopped attacker with a citizen’s arrest, where “if you catch a suspect red-handed, you can hold him until the police arrive”.

The victims of the stabbings were a 67-year-old American woman and a 69-year-old American man, a 26-year-old Polish man, a 73-year-old woman from Belgium and a 19-year-old woman from Amsterdam.

Officials have not concluded what motivated the attack, but said they are considering that it was a random spree and/or terrorism.

Amsterdam’s mayor, Femke Halsema, said: “The police investigation is in full swing and has full priority at the moment. We hope to soon get more clarity about the background of this horrible stabbing.

She added: “Our hearts go out to the victims, their families and loved ones.”

Amsterdam’s justice and security minister, David van Weel, said it was “much too early” to give details on the background to the attack.

He added that the investigation had not ruled out terrorism as a motivation.

In the aftermath, a trauma team was deployed via helicopter, which landed directly on the iconic Dam Square, and a large cordon set up.

According to a worker at the local De 3 Fleschjes bar, diners saw an older woman and a young girl being stabbed in the back before falling to the ground.

One shopkeeper told local newspaper Parool: “I heard a knock and then I saw a girl had been stabbed in the back and a boy ran off.”

Another witness told De Telegraaf they suddenly heard an “icy scream” before panic broke out.

A third person added she heard a lot of shouting and screaming as people were seen running on the streets.

A meeting at Amsterdam’s Stopera building was interrupted, and mayor Halsema was pulled out of a council meeting when news of the attack broke.

Anyone with footage of the incident has been urged to submit it to police to help the investigation.

Amsterdam suffered several stabbing last year carried out by people with mental health problems.

The council set up a hotline for residents to reports concerns about suspicious or irrational behaviour.

Thursday’s city-centre attack also follows a spate of terror-motivated violence across Europe.

A Syrian asylum seeker was charged with murder after a 14-year-old boy was stabbed to death in a knife rampage in Austria.

Officials say the 23-year-old was motivated by “Islamic terrorism” before his alleged role in the bloodbath attack that left five others injured.

And in Munich, a mum and her child tragically died from serious injuries after a suspected Islamist terrorist rammed his Mini Cooper into a crowd.

The woman, 37, and her two-year-old daughter were among the 39 injured in the “shocking attack” said to be carried out by a rejected Afghan asylum seeker.