Cops may have missed FOUR chances to arrest the suspected Huntingdon train knifeman, it emerged today.

Cambridgeshire Police admitted it had been called to three incidents in Peterborough prior to Saturday night's attack in which ten people were seriously injured.

It admitted officers didn't even visit the scene on one occasion.

Police in London were also called to investigate a stabbing in the early hours of the morning before the train stabbing but no-one was detained.

Cambridge Police has referred itself to the the police watchdog the IOPC.

The revelations came just hours after Anthony Williams, 32, of no fixed abode appeared in court charged with eleven counts of attempted murder.

In statement Cambridgeshire Police said that at 7.10pm on Friday (Oct 31) a 14-year-old was stabbed by a man with a knife in Peterborough city centre.

The police said that despite a search of officers and a police dog the offender was not found.

They said the stabbing, in which the victim suffered minor injuries, could possibly be linked to the stabbings on the Doncaster to London service on Saturday.

Just 15 minutes later at 7.25pm a knifeman entered Ritzy's barber shop in Fletton, Peterborough, with a large kitchen knife.

Cambridgeshire Police said "at the time of reporting the man was no longer there and had not returned, so we did not send officers"."

In the early hours the following morning (Nov 1)

a victim suffered facial injuries after being attacked at 12.46am with a knife on a train at Pontoon Dock station on the Docklands Light Railway (DLR) in east London.

Cambridgeshire Police confirmed that it then was reported that the knifeman had returned to the barbers in Peterborough at 9.25am later that day.

Despite arriving at the scene 18 minutes later, they were unable to locate the knifeman.

Today Cambridgeshire Police said it was reviewing all the incidents in Peterborough as" to understand whether there were any further potential offences."

In a statement it said: " British Transport Police retain primacy for the overall investigation, which will include these three incidents."

"We voluntarily referred ourselves to the IOPC for independent scrutiny of these incidents, as is standard practice in these cases."

Earlier today the owner Ritzy's barber shop confirmed a man had pulled out a knife at the store on Friday evening which had been reported to police.

Video shows him bending down to pick up a large kitchen knife which was on the floor and then gesticulating with the weapon in his hands.

Staff can be seen moving rapidly away from the knifeman.

Around 24 hours later Williams is accused of attacking passengers on a LNER service from Doncaster to London's King's Cross after he boarded at Peterborough.

The shop owner, who asked not to be named, said he believed the man who came into his business was Williams.

He said he called the police to alert them but declined to say what happened after that.

The barbers, which is less than a mile away from Peterborough station where Williams boarded the train, will remain closed this week.

In the shocking CCTV, a man believed to be Williams can be seen drinking from a small bottle in a black coat with his hood up.

The man can then be seen picking up a large kitchen knife and waving it around as staff scarper out the way.

This morning a police car was seen outside William's home in Peterborough.

Locals living on Langford Road in Peterborough say Williams' family home was ‘quiet' and they didn't see much of him.

There was no response from the three-bedroom semi-detached property Williams was understood to have lived, in Fletton, Peterborough.

Williams appeared at Peterborough Magistrates' Court this morning.

He has been charged with 10 counts of attempted murder, one count of actual bodily harm and one count of possession with a bladed article in Cambridgeshire.

Williams was also charged with one count of attempted murder in London in the early hours of Saturday (Nov 1) and possession of a bladed article in relation to the incident.

He has been remanded to appear at Cambridge Crown Court on December 1.

A spokesperson for Cambridgeshire Police added: "British Transport Police retain primacy for the overall investigation, which will include these three incidents."

"We voluntarily referred ourselves to the IOPC for independent scrutiny of these incidents, as is standard practice in these cases."