Military police have reportedly warned football supporters that an army of Argentine 'ultras' are planning to head to Brazil for the World Cup.
The authorities have expressed concern after it emerged that members of the Barra Brava hooligan group will team up with Brazilian counterparts when they arrive in South America.
Reports have claimed that the group will head to the city of Belo Horizonte on June 24 when England play Costa Rica in their Group D clash.
"We can normally monitor groups with a history of violence," the Daily Star quotes Belo Horizonte policeman Col Alberto Luiz Alves as saying.
"But we would only know of dangerous fans if they enter by air, and in the case of the Barra Brava, most will be arriving by land. It will be very difficult to keep track of them."
The Argentina squad are based in Vespasiano for the tournament.