The Gothia Cup, or World Youth Cup, this year featured teams from 77 nations this year, including four teams from Ethiopia.

According to Swedish police, the hosts at a school where 20 Ethiopians connected to one of the teams were staying discovered on the day of the final that the team and several of the adults accompanying them had disappeared.

"From our perspective it's strange because this is a team that we have a good relationship with," Fredrik Beckman, press spokesperson at Gothia Cup, told the Göteborgs Posten newspaper.

He said that the tournament's management had filed a report to the police as a "precautionary measure", and now – ten days after the end of the tournament – the team was still missing.

The last correspondence that the organisation received from the Ethiopian team, according to the Expressen newspaper, the club's contact person thanks them for their "consideration" and adds that "it seems that the problem was a communication problem."

But in the email, the contact person gives no information on where the team are or whether they have returned home.

Police have confirmed that the group have not returned to Ethiopia and believe that they disappeared on their own accord.

"We have no idea if they're trying to stay in Sweden. That would just be speculation," Ellinor Halldin, from the unit for missing people at the Swedish police's western region, told The Local.

"In the past, we've had disappearances before in the Gothia Cup but never so many as this. Those have been for different reasons, either they've already gone home or they've wanted to stay in Sweden or another country."

She said her unit was working with the Migration Agency, the Swedish border police, and authorities in other countries to try and find the missing people, and expected to get notified if one or more of the missing people attempted to cross a border or was encountered by the authorities for another reason.

"There is no indication that anything illegal lies behind this, such as people smuggling or something similar," she told the Göteborgs Posten newspaper. "My experience is that they usually trickle in gradually in the end."