A teenager has been found guilty of murdering a boy who was fatally stabbed with a Rambo-style knife after turning up for a “little scrap” about a mobile phone.

Anas Mezenner, 17, died from a 15cm deep wound to the buttocks following a stand-off between two groups of youths in Haringey, north London, on January 19, the Old Bailey was told.

The stand off started over a friend’s missing phone at Willow Walk, but escalated as at least three of the opposing groups were armed with large knives, jurors heard.

Shortly after 7.40pm, the group returned to a quiet residential area for 90 minutes and engaged with a stand off.

Footage recorded on a mobile phone, by a 17-year-old who inflicted the attack, showed play-fighting and people posing with large blades.

While on remand awaiting trial, the 17-year-old also let slip in a recorded phone call that he had wanted “my first little juice (blood) on my blade”.

During his Old Bailey trial, he admitted stabbing Anas but claimed it was self-defence.

He also indicated where he had stashed the weapon – a large Rambo knife – near bins on a local estate.

Two other 17-year-olds and a boy aged 14 admitted being nearby when it happened but denied involvement in the pre-arranged meeting.

A jury deliberated for 12 hours to find the teenager who inflicted the fatal blow guilty of murder, while the other two 17-year-old co-defendants were convicted of manslaughter.

The boy wielding the knife was further convicted of wounding with intent against one of Anas’s friends, while a second 17-year-old was convicted of a lesser charge of unlawful wounding of the same boy.

The 14-year-old was acquitted of both murder and manslaughter, and of any attack against the second victim.

During the trial, prosecutor Tom Little QC said it was a “senseless murder”.

The defendants “lived by the knife and they were willing to kill with knives”, he alleged.

Jurors were shown CCTV footage in which it was alleged that words were exchanged before the victim and his friends fled.

Shortly after, Anas re-appeared on CCTV touching the area of his buttock where he was stabbed.

Anas was able to make a 999 call before he collapsed and was found by police slumped against railings.

Although he was rushed to hospital, he died the next day.

A post-mortem examination found Anas died from a 15cm deep stab wound to the left buttock, and he also suffered cuts and bruises and two fractured teeth.

Anas’s injured friend told police that one of the attackers had shouted “sauce (stab) him”.

As he ran away he felt one of them “poke him” in the back, the court heard

Afterwards, he considered whether they had been “set up” or ambushed, the court was told.

The other friend said the opposing group pulled out knives, one with a blade around 20in long.

Jurors heard police recovered two knives from a Chrysler Voyager parked nearby which was allegedly linked to some of the defendants.

The car keys and a Zombie knife were found at the home of one of the accused teenagers, jurors were told.

In a phone call from prison, the 17-year-old stabber referred to what he had done.

He said: “Just wanted my first little chinging you get it, my first little juice (blood) on my blade.

“It’s just gone in my man’s arse… the whole 15 went in down his arse.”