London, United Kingdom (AFP) – A UK appeals court on Thursday increased the sentences of two boys believed to be Britain’s youngest knife murderers.

The pair, now 13, were convicted in June of killing a stranger in a machete attack when they were aged just 12.

They were later handed life sentences for the killing of Shawn Seesahai, 18, with the minimum period before they could be considered for parole set at eight-and-a-half years.

But the Court of Appeal ruled that the sentences had been “unduly lenient” and should be increased to 10 years.

The two boys cannot be identified legally because they are minors.

Described in court as the country’s “youngest knife murderers”, they are also believed to be the youngest convicted of murder in Britain since 1993.

Due to their age, the boys have not been jailed but held in secure accommodation. Once they are deemed fit for release, they will be monitored for the rest of their lives.

The case highlighted mounting public concern about knife crime in the UK.

Seesahai’s family said after the tougher sentence was imposed that “we recognise that justice has been served today”.

The ruling “better reflects the gravity of the actions that took him from us and acknowledges the immense loss we live with every day,” they added.

In London alone, the number of knife or sharp instrument offences recorded by the police between March 2023 and March 2024 rose to more than 15,016 — up from 12,786 in the same period the year before.

Prime Minister Keir Starmer in September launched an initiative to stop young people getting involved in knife crime, which he called a “national crisis”.

As part of a government commitment to halve knife crime, a ban on “zombie” style weapons and machetes with blades of over 20 centimetres (eight inches) also came into force in September.