Yuusuf Warsame, eight, was visiting family in Gothenburg when projectile was thrown into flat in possible gang-related attack

An eight-year-old schoolboy from Birmingham has been killed after a grenade was thrown into an apartment where he was sleeping in Sweden.

Yuusuf Warsame was visiting family in Gothenburg when the explosive was thrown by an unidentified attacker through a window of the third-floor apartment early on Monday. He died from his injuries in his mother’s arms on the way to hospital. The attack has been linked to a gangland feud.

Yuusuf, a pupil at Nelson Mandela primary school in Sparkbrook, Birmingham, was on holiday with his mother and siblings, and had celebrated his birthday on 15 August.

Emergency services were called to the block of flats in the Biskopsgården neighbourhood at about 3am. Police said Yuusuf was sleeping in the living room of the apartment at the time of the attack, which Thomas Fuxborg, a spokesman for Gothenburg police, described as abhorrent and despicable.

Yuusuf’s father, Abdiwahid Warsame, told the Birmingham Mail that the boy’s nine-year-old sister, Aisha, and five-year-old brother, Ahmed, were asleep in the same room but escaped with just “a few little scratches”. At least five children and several adults were in the apartment at the time and the father of seven said it was a miracle that they had not all been killed.

“He was a lovely boy, a beautiful child,” he said. “He was so well liked at school and really worked on his education. He wanted to do well in life and not make bad decisions. He was just a normal boy with his education ahead of him.”

Warsame, a Dutch national, told the newspaper that authorities in the Netherlands needed a copy of Yuusuf’s death certificate before they could issue travel documents permitting him to join his wife in Sweden.

Warsame has been in the UK, where Yuusuf was born, since 2001, and owns a halal butcher and grocery story in the Small Heath area of Birmingham.

Swedish media linked the violence to a gangland feud and quoted police as saying a man convicted of a fatal shooting last year was registered at the address. In March 2015, armed men burst into a pub in Biskopsgården, killing an innocent bystander and a man known to police.

Earlier this month, eight people were convicted of the attack, which took place in the context of a continuing conflict between members of Gothenburg’s Somali community, and given prison sentences ranging from seven years to life.

While Sweden is generally peaceful and safe, with low crime rates, police have had difficulty addressing violence in poorer neighbourhoods in Stockholm, Gothenburg and Malmö. In recent years, there have been grenade attacks, shootings and incidents of cars being set on fire.

The prevalence of arson has been a key subject of political debate over the summer, with cars being set alight on an almost nightly basis. The centre-right opposition Alliance has called for the hiring of an additional 2,000 police officers, while the leftwing government has proposed a series of crime prevention measures.