Visitors pose with Pokemon character Pikachu during the opening day of the Pokemon Go Safari Zone.

Tens of thousands of Pokemon Go fans descended on a Taiwan park Thursday hoping to catch a rare "Heracross" and other elusive virtual creatures from the popular game.

The four-day Pokemon Go Safari Zone in New Taipei City is expected to attract up to half a million fans of the cute fighting creatures.

Pokemon characters (L to R) Scorbunny, Grookey, Pikachu and Sobble perform.

Pokemon Go has sparked a global frenzy since its launch in 2016 as users of the gaming app hunt for virtual cartoon characters overlaid on real-world locations using augmented reality technology.

"We can wander out of the city and see what creatures we can catch. It's a hobby and a form of exercise," said Chuang Jung-chung, 66, accompanied by his wife and another retired couple on their hunt around the huge park.

Among their quarry are the blue Heracross, which resembles a rhinoceros beetle and is unique to the Taiwan event, and the eyeball-shaped "Unown".

Visitors play Pokemon Go on their phones during the opening day of the Pokemon Go Safari Zone.

Pokemon Go has been praised for motivating people to become more active and Japanese fan Kaori Nishijima travelled all the way from Tokyo hoping to catch the elusive Taiwan creatures.

"I am a heavy player in Japan. I think this is good for the health... You can walk and play at the same time," she told AFP, dressed in a "Pikachu" cape despite the heat.

Last year, the first annual Pokemon Go event was held in the southern city of Tainan and attracted more than half a million visitors in three days.

Visitors gather for the opening day of the Pokemon Go Safari Zone.

The game is very popular in Taiwan, which has one of the highest percentages of players in the world, said Hikaru Ray Adachi, senior director of product marketing at Niantic, which releases the

Nintendo mobile game app.

"For Pokemon and Pokemon Go, Taiwan is very important," he said.

Agence France-Presse