A four-year-old boy is reported to be one of three people killed after an SUV ploughed into a crowd of people in Graz, Austria.

Another 34 people were injured in the attack, with six - including two children - said to be in a serious condition.

Eyewitnesses say the driver rammed into crowds at up to 90mph before he got out and began randomly stabbing bystanders, which included the elderly and policemen.

The three victims killed in the attack have been described as a 28-year-old Austrian man, a 25-year-old woman and a four-year-old boy.

The woman and boy were both killed as the driver ploughed through crowds on the main Herrengasse shopping street before reaching the city's main square.

The governor of the state has described the driver as a 'deranged lone assassin'.

The National Police Director, Josef Klamminger, said the man, who is believed to be a 26-year-old Austrian truck driver, was suffering from 'psychosis' related to 'family problems'.

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Attack: A man deliberately drove his car into a crowd of people in Graz, Austria, before getting out of the vehicle and stabbing people at random

Lost: Three people were killed when the driver sped through the busy shopping district at up to 90mph

Aftermath: Items of clothing were left strewn all over the road after the horrific incident in Graz - Austria's second biggest city

Rampage: The driver killed two people while speeding up Herrengasse road towards the main square in Graz, where he ploughed into an outdoor dining table full of people, a police spokesperson said

Emergency: Paramedics treat one of the 34 injured people on the side of the road and the town's mayor has said at least one is in a critical condition

Response: About 60 ambulances converged on the scene and four helicopters scrambled to bring the victims to hospital

Disaster: The Provincial mayor of Graz - Austria's second city - said at least one of his injured victims is in a critical condition

The attacker is believed to be married with two children.

Police director Klamminger added that the man was under a restraining order keeping him away from the home of his wife and two children, after a domestic violence report was filed against him last month.

The driver did not resist when he was arrested by the police - who say he acted alone - and they have no reason to believe it was an act of terrorism.

He killed two people while speeding towards the main square where he ploughed into an outdoor dining table full of people, a spokesperson for the regional police said during a press conference today.

One of those killed is reported to have been on a bicycle when they were hit by the dark green SUV.

Crowded: The busy square was hosting an event related to the Austrian Formula One, being held 80km away at the Red Bull Ring in Spielberg, in Steiermark

Stunned: Shocked residents of the city tweeted photos of the aftermath of the scene, showing emergency services personnel filling the area

Emergency services: An estimated 60 ambulances converged on the scene and the Austrian auto club sent four helicopters to bring the victims to hospitals. Firefighters also arrived at the scene

The man is reported to have stopped the car outside a local business, got out of the car and attacked a couple with a knife.

The busy square was hosting an event relating to the Austrian Formula One Grand Prix which is being held 80km away, in the Red Bull Ring in Spielberg, in Steiermark.

A local resident told Sky News that her friend saw people flying through the air, adding: 'Apparently he was attacking elderly people with a knife.'

Carnage: Eyewitnesses report seeing two bicycles lying on the ground, that had been run over by the dark green SUV. One of those killed in the attack was said to be on a bicycle when they were hit

Recovery effort: Spray-paint markings covered the ground in the square, as the emergency services attempted to get to grips with the carnage

Horror: Eyewitnesses of the attack reported pedestrians running into nearby shops to take shelter, before emerging to see bodies lying 'face down' in the street

Dr Sea Rotmann says her friend told her how the driver was 'doing between 100km-an-hour and 150km-an-hour' on the busy road.

A waitress at the Pronto restaurant on the main square told the Kleinezeitung website she heard screaming before she even saw the driver.

Simone Zucca added: 'He raced through the front of the restaurant without braking... He then caught a boy who was thrown against the wall.'

Another eyewitness told the BBC he saw bodies lying on the ground 'covered in blood'.

Other witnesses described the sound of the SUV knocking chairs in the square flying as being 'like gunfire'.

About 60 ambulances converged on the scene and the Austrian auto club sent four helicopters to bring the victims to hospitals.

The city council released a statement which read: 'At 12pm there was an appalling incident in the centre of Graz, which has caused major alarm and left the city deeply shaken.'

Alarm: Around 60 ambulances converged on the busy shopping district in Graz this afternoon

Harrowing: A resident who witnessed the aftermath in Graz told MailOnline it was 'shocking to see a young child dead'

Austria's APA news agency said two bodies were lying near the scene and were covered with blankets

Provincial Governor Hermann Schuetzenhoefer said at least one of his injured victims is in a critical condition.

He added: 'We are shocked and dismayed... there is no explanation and no excuse for this attack.

'We have much to do to ensure cohesion in our community, which has clearly become difficult for many people.'

Weapon: The dark green SUV that was used in the attack being removed from the area

Tragedy: More than 600 turned out for a memorial held for the victims of the attack, which took place at the Grazer Stadtpfarrkirche church in the centre of the city

Attacker: Local media has reported that the man driving the SUV is a married father-of-two, of Bosnian origin

The incident took place in Graz, Austria's second largest city, and police officers have now sealed off the area.

German-language website Krone reported that the man arrested by police is of Bosnian origin.

'People were screaming in panic and ran into the surrounding shops to get to safety', an eyewitness told the website.

Police chiefs told the Austrian Kleine Zeitung newspaper that the suspect got out of the SUV and started stabbing people with a knife.

Memorial: Hundreds of stunned residents of the city turned out this evening to light candles and attend a remembrance ceremony in honour of the dead and injured

Austria's APA news agency said two bodies were lying near the scene, covered with blankets.

Bishop Wilhelm Krautwaschl, the Bishop of Graz, shared his condolences on Facebook.

'I am shocked by what's happened, I pray for the victims and for those who have rushed to help then', he said.

The victims were remembered at a memorial service this evening, which took place at the Grazer Stadtpfarrkirche church in the centre of the city.

More than 600 mourners gathered at the church to pay their respects to the victims, while the city has launched an online book of condolence, according to German language site Welt.

Grief: The square was packed with people who gathered to honour the dead and injured, while the city has launched an online book of condolence that has already received hundreds of messages

Gathering together: Residents of Graz came together this evening for the memorial service and to light candles and lay floral tributes in the square

Hundreds of messages of support have already been posted on the website, and dozens of floral bouquets, candles and messages of mourning have been placed at the site.

Mayor Siegfried Nagl - who was himself an eyewitness to the attack - ordered black flags of mourning flown from all municipal buildings and cancelled street fests and other city events.

The mayor was reported to be riding his Vespa in the street when the SUV sped past him, just feet away.

He only avoided being hit by driving onto the pavement, according to local media.