Two men came to blows outside Plaza Singapura on Sunday, earning them the dubious distinction of becoming the first people to be arrested here because of Pokemon Go.

The driver, 28, had honked at the 33-year-old pedestrian, who was apparently playing the popular mobile game while crossing the entrance to the mall's carpark in Handy Road, sparking an argument which led to the fight.

A witness, who gave her name only as Ms Zeng, said she was smoking outside the mall when she saw them being handcuffed by police.

"I saw two policemen talking to two men at the carpark entrance for about five minutes," said the 25-year-old sales assistant. She said one of the men had a ponytail and a mole on his face.

The Singapore Police Force said the men were arrested for the offence of affray and, if found guilty, face a prison sentence of up to one year or a fine of $5,000, or both.

Since its launch here on Aug 6, Pokemon Go, a game that requires players to be on the move to capture virtual creatures, has created a stir - among both its fans and detractors. It has had more than 100 million downloads worldwide.

Residents near PokeStops, for instance, where players can get free items to catch or attract Pokemon, have complained about being inconvenienced by distracted players.

In Hougang Avenue 10, scores of players have been seen jaywalking or running across the road towards a park that is a PokeStop. They also leave rubbish behind.

Mr Shahjehan Ibrahim Kutty, who lives in Block 416, said Pokemon Go players have been hogging parking spaces at his carpark.

"Give me back my carpark," said the 48-year-old finance manager.

Lawyer Chia Boon Teck warned that players risk running afoul of the law if they are not careful.

"The most common offence that players are likely to commit is set out in Section 13(1)(e) of the Miscellaneous Offences (Public Order and Nuisance) Act which makes it an offence to obstruct or interfere with the traffic in any public road while playing any game or using any telephone," said the co-managing partner of Chia Wong LLP.

Mr Chia said players "who cause any common injury, danger or annoyance to the public" could also be considered a public nuisance, and fined up to $1,000 for the offence.

Safety concerns have been raised after online videos showed drivers playing while behind the wheel.

Netizen Paul Chan, who posted a photo on Facebook of a taxi driver playing a game, claimed the driver continued even after the passenger asked him to stop. "The driver told her to mind her own business," the 52-year-old security officer told The Straits Times. "Thank God the journey ended without incident."

Elsewhere, the game has been linked to crimes against unsuspecting players. In Missouri in the United States, armed robbers lured victims to isolated spots with the promise of Pokemon to be caught. In Japan, a man was arrested for molesting a woman engrossed in the game.

During yesterday's Parliament sitting, several MPs raised concerns about problems caused by Pokemon Go and other augmented reality games in the future.

"Again, and increasingly, consumers have to accept responsibility for playing the game," said Nominated MP Ganesh Rajaram.