Forget beach volleyball, soccer or tennis, not to mention the steeplechase or discus. "Pokemon Go" is challenging the Olympics for most popular game among some young Brazilians.

Hundreds of them turned out in a Rio de Janeiro park on Saturday holding their mobile phones to hunt for virtual creatures in the hyper-reality game app that has become a craze in Brazil since its release two days before the Games.

"I went to a soccer game to see Brazil play Sweden, but after 'Pokemon Go' started I lost interest," said student Lourdes Drummond at the Quinta da Boa Vista park, once the gardens of the Brazilian royal family.