Two 12-year-old boys are thought to have become the youngest knife murderers in the UK after being found guilty of a brutal machete attack on a “loving and protective” teenager who was stabbed through the heart in a Wolverhampton park.

On Monday, jurors unanimously convicted the youths, who are believed to be youngest defendants convicted of murder in Britain since Robert Thompson and Jon Venables, both aged 11, were found guilty in 1993 of killing two-year-old James Bulger.

Family members of both the victim, Shawn Seesahai, and the defendants cried and hugged each other in the public gallery as the jurors found both boys guilty of murder and one guilty of possessing a bladed article.

In an interview released after the verdicts, Mr Seesahai’s parents Suresh and Maneshwary have said they will never be able to get over the loss of their 19-year-old son who always told them he would “shine” and take care of them.

Speaking for the first time since their son was murdered, Suresh Seesahai said he feels sorry for the parents of the killers and only hopes that “justice” is served for his son.

A month-long trial at Nottingham Crown Court was told Mr Seesahai was shoulder-barged by the smaller of the two defendants, who “often” carried a machete with a 42.5cm-long blade, before being punched, kicked, stamped on and “chopped” at with the weapon.

The victim’s friend told the trial he was forced to run for his life but Mr Seesahai stumbled as he tried to flee from the boys on Wolverhampton’s Stowlawn playing fields on November 13 last year.

After refusing to answer police questions in the aftermath of the murder, the boys both gave evidence to jurors, blaming each other for inflicting the fatal blow.

As well as failing to summon help for Mr Seesahai, the youths showed no remorse for what they had done in the 24 hours before their arrest – with one cleaning the machete with bleach and hiding it under his bed.

They told the court they both played video games in the hours after the killing, claiming they did not know Mr Seesahai had died until the following day.

Jurors heard one of the defendants posed, wearing a mask, with the murder weapon for a picture hours before the killing, and was found to have 11 areas of bloodstaining on his clothing.

The boy was also seen with blood on his hands in the aftermath of the murder, while his friend had a small area of bloodstaining on his right trainer.

Mr Seesahai, a stranger to the two boys, was pronounced dead at 9.11pm after police and paramedics were called to the scene.

At the start of the trial, prosecutor Michelle Heeley KC told the court Mr Seesahai, who lived in Handsworth in Birmingham but was originally from Anguilla in the Caribbean, had travelled to the UK to receive treatment for cataracts.

Ms Heeley said the weapon had been taken out of one of the boys’ trousers and was made available to be used “despite the fact Shawn Seesahai and his friends had offered no violence, nor done anything to offend (the youths)”.

The court heard that the friend managed to escape and looked back to see Mr Seesahai on the floor, having tripped on a grassed area.

Although the friend did not see the “vicious attack” that ensued, Ms Heeley said a teenage girl who had been with the 12-year-olds told police that both had been in possession of the machete and one often carried it.

The witness described seeing one boy pick up the machete and hold it in the air, Mr Seesahai falling to the floor and then being punched and kicked.

Ms Heeley added: “She told police she saw (a defendant) using the machete on Mr Seesahai’s legs, and also saw (the other defendant) punching and stamping on his head.

“The prosecution say the two boys were engaged in a joint attack upon a man who had done nothing wrong, a man with no weapon, who was utterly defenceless on the ground.

“We say that these two boys were acting together and meant to kill Mr Seesahai, at the very least they intended to cause really serious harm.

“As a result of their actions, Shawn Seesahai died at the scene. He had been hit so hard to the skull with the machete that a piece of bone had actually come away.

“He had slash wounds on his leg and most significantly he had an injury from the machete that went through his body all the way from his back, through his ribs and into his heart.”

High Court Judge Mrs Justice Tipples thanked the jury for their “hard work and determination” in what has been a “tragic and distressing case” on the case after their verdicts were delivered on Monday afternoon.

In an interview, Mr Seesahai’s parents have questioned how a child so young could have a weapon like a machete with them as they walked the streets.

Suresh Seesahai said: “This world is a different world, kids are dangerous now. If we don’t pay attention to them this will keep happening.”

Mrs Seesahai added: “Twelve-year-old kids should be at home doing school work and then going to bed. I have two children and at 7.30pm they had to go to bed because they have to follow the rules of the house.

“Before that they do their school work and have a little rest.”

The couple, who also have a teenage daughter, told of the moment they were told their son had been stabbed to death.

Mrs Seesahai said: “I got a call from Shawn’s friend who was staying with him. He told me Shawn had been stabbed and I just started crying.

“I told my husband and he asked for the phone to find out what had happened.”

Mr Seesahai added: “She kept saying that Shawn had been stabbed, I asked her what she meant and then she handed me the phone.

“I asked if Shawn was OK and he said that he was not, that he had passed away.

“About 30 minutes later I got a call from the police who asked if I was Shawn’s father and if I could spell Shawn’s name out. I said ‘yes’ and did, they told me they had bad news – that my son had been stabbed and had passed away.

“Getting a call like that is not nice for anyone. I tried to keep myself up but getting a message like that was not easy.”

The boys are expected to be sentenced on a date to be fixed in July.