Police believe a teenager stabbed in a suspected far-right terror attack in Surrey may have been targeted because of his appearance.

The 19-year-old was injured in Stanwell on Saturday evening by a man who is alleged to have shouted far-right and racist comments before the attack, while armed with a baseball bat and a knife.

Police say they do not know if there was any link to the white supremacist massacre in two mosques in Christchurch, New Zealand, in which 50 people were killed.

The victim of the Stanwell attack, who police say is from southern Europe, was stabbed in a Tesco car park and suffered serious hand injuries.

Police said a 50-year-old man had been arrested on suspicion of attempted murder and a racially aggravated public order offence. He remains in custody and is being questioned by counter-terrorism detectives.

Det Supt Nigel Doak, from Counter Terrorism Policing South East, said: “Whilst this investigation remains in the early stages, it has continued to show the hallmarks of a terrorist event. It is believed that the offender made racial comments and statements, promoting extreme far-right views before carrying out the attack.

“We believe the victim, a 19-year-old southern European man, may have been targeted due to his ethnic appearance.

“Police are committed to tackling all forms of toxic extremist ideology, which has the potential to threaten public safety and security. Extreme rightwing investigations are pursued by our officers with the same level of resource and determination as other forms of extremist ideology.”

Police say they were first called at 10.18pm “to reports of a man acting aggressively and shouting racist comments whilst carrying a baseball bat and a knife. Several nearby vehicles were also damaged.”

They were called again 50 minutes later. They said: “It was reported that a man had been stabbed in the Tesco car park in Town Lane. It is believed that the suspect for the attack was the same man who was reported as acting aggressively earlier that day. Surrey police, including armed officers, were quickly on scene to search for the suspect.” Officers confirmed a man was detained at 11.11pm.

Police said the teenager had suffered serious injuries to his hands and fled into a nearby McDonalds for help. He was treated in hospital where he underwent surgery and was discharged on Monday.

A spokesperson added: “Counter-terrorism policing have been liaising with Surrey police … Yesterday, the senior national co-ordinator, DAC Dean Haydon, made the decision to declare the incident a terrorism incident and therefore it is right that the public were informed.”

A suspect was arrested first by Surrey police on Saturday evening. After the decision that the attack may have been a terrorist one he was re-arrested at 7pm on Sunday by counter-terrorism detectives under the Terrorism Act.

On Monday Westminster magistrates granted a warrant for his continued detention until Saturday while the investigation continues.

Police have increased patrols in the area.