The Southport stabbings have been described as among the worst knife attacks in Britain since 2017.

Flowers and teddies were being left at the scene in the Merseyside seaside town on Tuesday by those mourning the deaths of two children after the “ferocious” knife attack at a Taylor Swift-themed dance class.

Six other youngsters remain in a critical condition in hospital while a teenager is being questioned by police over the incident.

The killings are the latest in a string of horrific stabbing sprees in the country over recent years and come just months after another attack in east London.

(PA Graphics)
(PA Graphics)

– April 30 2024: Hainault

Daniel Anjorin, 14, died near his home as he walked to school in a sword attack which also left four people injured – including two police officers.

Marcus Arduini Monzo, 36, a dual Spanish-Brazilian national living in Newham, east London, has been charged with Daniel’s murder, two counts of attempted murder and two counts of causing grievous bodily harm with intent.

He was also charged with aggravated burglary and possession of a bladed article and is due back in court in September.

Daniel Anjorin funeral
Daniel Anjorin, 14, died in a sword attack earlier this year (Jonathan Brady/PA)

– June 13 2023: Nottingham

Valdo Calocane was sentenced to an indefinite hospital order after stabbing Barnaby Webber and Grace O’Malley-Kumar to death as they walked home from a night-out in the early hours of June 13 last year, before killing 65-year-old Ian Coates and stealing his van.

He then used the vehicle to knock down three pedestrians – Wayne Birkett, Marcin Gawronski and Sharon Miller – in Nottingham city centre before being arrested.

Prosecutors accepted his not guilty pleas to murder after multiple medical experts concluded he had paranoid schizophrenia, with him instead admitting manslaughter by diminished responsibility.

Sentencing Calocane, a judge told him his “sickening crimes” meant he likely be held in a high-security hospital probably for the rest of his life and ruled he would be subject to further restrictions if ever discharged, which would need to be approved by the Justice Secretary.

Valdo Calocane court case
Valdo Calocane is being detained in a high-security hospital after the attack in Nottingham last year (Nottinghamshire Police/PA)

The handling of the case has prompted outcry and led to numerous ongoing inquiries into the police and other public bodies involved. Senior judges have since ruled his sentence was not unduly lenient and his condition was the sole identified cause of the crimes.

– June 20 2020: Reading

Earlier this year, a coroner concluded the Reading terror attacks were “probably avoidable” and the deaths of three men were “contributed to by the failings of multiple agencies”.

Failed Libyan asylum seeker Khairi Saadallah shouted “Allahu akhbar” as he fatally stabbed friends James Furlong, 36, Dr David Wails, 49, and Joseph Ritchie-Bennett, 39, on June 20 2020 in the Berkshire town’s Forbury Gardens.

Three other people – Stephen Young, Patrick Edwards and Nishit Nisudan – were also injured before Saadallah threw away the 8in (20cm) knife and ran off, being chased by an off-duty police officer.

Forbury Gardens memorial service
Friends had been enjoying the summer weather in Reading’s Forbury Gardens when Khairi Saadallah carried out his attack in 2020 (Steve Parsons/PA)

Saadallah was briefly known to MI5 prior to the attack but the information given to the security service, that he planned to travel abroad possibly for terrorist purposes, did not meet the threshold for investigation.

He fought for the extremist Ansar al-Sharia group in Libya and, since arriving in Britain in 2012, racked up convictions for a string of crimes. While in prison he sought out a radical preacher and carried out the attack just weeks after being freed from jail, and a day after he was visited at his home by police officers who failed to find a knife.

His behaviour deteriorated from 2018 when carrying weapons around in public demonstrated his “propensity to attack others”, the coroner said. Failures including in assessing his extremist risk and giving him mental health support were identified.

– February 2 2020: Streatham

Sudesh Amman, 20, was under 24-hour police surveillance when he stabbed two people while wearing a fake suicide vest on a south London high street.

He had been released from prison on January 23, after being jailed in December 2018 for possessing and distributing terrorist documents.

At the time of his release, he was viewed as an “extremely concerning individual”.

He was killed by police marksmen after launching his attack.

In the wake of the atrocity, then-Metropolitan Police boss Dame Cressida Dick said the surveillance was not “man-to-man marking”.

– November 29, 2019: Fishmongers’ Hall

Usman Khan was shot by armed police on London Bridge, approximately 15 minutes after he strapped kitchen knives to his hands and fatally stabbed Cambridge University graduates Jack Merritt and Saskia Jones at nearby Fishmongers’ Hall.

Incident at London Bridge
Usman Khan was confronted by members of the public in the wake of the 2019 Fishmonger’s Hall attack (Metropolitan Police/PA)

He was jailed in 2012 for plotting a terror camp in his parents’ homeland of Pakistan, and was known in prison as the “main inmate” for extremist views.

Khan was so notorious, in fact, that he was classed as being among the top 0.1% of the most dangerous prisoners in England and Wales when he was released into the community as a category A, high-risk offender on Christmas Eve 2018.

MI5, which had already launched a covert investigation with West Midlands Police supported by Staffordshire Special Branch, had intelligence that Khan was planning to “return to his old ways” and aspired to carry out an attack.

Yet the information was not passed on by police to others involved in Khan’s management in the community and the “old ways” intelligence was labelled “low grade”.

An inquest jury concluded failings in Khan’s management in the community and information-sharing and guidance by agencies responsible for monitoring or investigating Khan contributed to the deaths.

– June 3 2017: London Bridge and Borough Market

Khuram Shazad Butt, 27, Rachid Redouane, 30, and Youssef Zaghba, 22, killed eight people and injured dozens more when they ploughed a van into pedestrians on London Bridge and then began stabbing people around Borough Market.

Butt had previously come to the attention of MI5 in 2014, under an alias, as part of an investigation into potential terrorist attack planning in the UK. He was investigated for various periods over the next three years.

In early 2016, Butt appeared in a Channel 4 documentary called The Jihadis Next Door, which was watched by MI5 staff.

Incident at London Bridge
Eight people were killed and dozens injured in the 2017 London terror attack (Isabel Infantes/PA)

He had brushes with the law, including being arrested for fraud in October 2016, but there was not enough evidence to bring charges.

All three attackers attended a gym that was owned by a suspected extremist and member of banned group al-Muhajiroun, although MI5 failed to identify the site as being significant.

Zaghba nearly outed himself in March 2016, when he was stopped trying to fly from Bologna to Istanbul.

He accidentally told airport officials he was travelling “to be a terrorist”, before correcting himself to “tourist”.

Italian officials put a serious crime alert on Zaghba, and the following month contacted MI5 for more information but received no response. This was put down to an admin error.