Panic on the streets of Rio: Bitterness rises between Brazil and Argentina fans ahead of Maracana final

São Paulo tube is packed with Brazilians and Argentinians on the way to Arena Corinthians for the World Cup semi-final. The Dutch are no more than bystanders. It is all very quiet until the blue and white fans start counting till seven, altogether. Some of the hosts smirk, others get silently angry and decide to begin another count, this one till 28 – the number of years that Argentina haven't lifted football's holy grail.

It is only sport, the Argentinians think. Some actually laugh at the count. But the hurt Brazilians, who only recently discovered catchy songs to go at Argentina, start calling Diego Maradona a cocaine sniffer. And then they go with pro-Holland chants. And then they tell Argentinians to go f*** themselves. Argentinians decide to stop the dialogue. They sing their own songs louder and louder so they can be heard in the middle of the Brazilian sound barrier.

That is even quite polite considering the brawls that South American fans have become used to seeing in the last few years. The rivalry between Brazil and Argentina was forged in club football, especially in the Libertadores Cup. When Argentina won their first title, Brazil had done it three times already. That's why many fans are actually OK with supporting the other nation. But not as much in this World Cup, which has made their footballing relation grow more and more bitter.

"I never thought Brazilians would get so upset with our chants, we love coming here and they won loads in the last decades. We won nothing since 1986," says salesman Esteban Gomez, 45. "But that is OK. If we are champions at their home we will annoy them more." Ask any Rio resident what his worst nightmare is and that will involve happy Argentinians after the final at the Maracanã stadium. About 70,000 Argentinians are expected in the Marvellous City.

Brazilian engineering student Eduardo Tanaka, 25, is so anti-Argentina that he travelled to Rio without any tickets just "to see their doom against Germany". What ever happened to South American unity, wonders FFT. "I like the nation Argentina. That doesn't mean I have to support their team so they win here," he says. "They have been against Brazil for ages. Why should I support them now?"

Both Argentinians and Brazilians expected the final to be played between themselves. Germany decided to ruin that plan in great style. But that has not stopped locals from carrying on with their anti-Argentina slogans even on the streets. Many of them respond to their neighbours' claim that Maradona is better than Pelé and that they are Brazil's "father", in reference to the superiority of their clubs in clashes against Brazilian sides.

Argentinian Claudio Zapata, 32, lives in Rio and says the bitterness will end once the trophy is handed to the winner. "This is the most tense moment in Brazil-Argentina relations. I have to watch what I say because many visiting fans are exaggerating too," he says. "To Argentina, England will always be the biggest rival. But that can change on Sunday if we lose and Brazilians celebrate Germany too much. I am actually worried."

Brazil authorities have stepped up security for the final by putting military police in the Maracanã, which was guarded by weaponless FIFA stewards in previous matches. Whatever happens on Sunday, it is sure that this World Cup has forever changed the relation between fans of two of the most football crazy nations on Earth.