"I was startled to see a stranger suddenly standing in front of my house this morning, only to realise later, there was a 'Pokemon' on the roof!"

Recalling the frightful moment, Lum Choi Yan,24, said she was at first alarmed to see a man at her front door, pointing his mobile phone to the roof of her house.

The private sector employee almost called the police as the man was acting suspiciously.

"When I asked what he wanted, he said he was chasing after a 'Pokemon' which had flown over the roof from the playground nearby," she told Bernama.

Lum said many people were already hooked and if not careful the game could be a safety hazard and public nuisance as reported in several countries.

"I for one, dare not download the application. My friends are so into the game that they are not aware of their surroundings, including crossing the street blindly," she said.

Private university student Lily Ferawati Rofil, 27 said 'Pokemon Go' players could easily be detected especially at crowded areas.

"I have downloaded the application and found that the players' target areas to hunt 'Pokemon' were at houses of worship such as mosques and temples, high rise buildings or secluded areas.

"For example, if you will see secluded places with damaged signboard or behind a public toilet suddenly swarmed by people, all because of the game."

However, she said public and personal safety should not be ignored and care should be taken not to wander onto properties where you are not allowed.

Tieu Chect Hou, 28, said a teenage girl who was so engrossed hunting Pokemon almost walked into him while he was having lunch at a restaurant in Pudu.

"I saw her walking up and down with a mobile phone in hand and smiling by herself. She was so oblivious to her surroundings, bumping into people without apologising.

"I only realised she was playing Pokemon Go after tailing her from behind," said the civil engineer.

He said since Pokemon Go was launched many people had been acting strangely, gathering at certain spots to play with their phones and causing traffic jams.

Pokemon Go, a location-based augmented reality game officially launched on July 6, entered the Malaysian market and over 30 other countries yesterday.

The application developed by Niantic Incorporation of Nintendo USA is a conventional stealth game where players must hunt and fight with virtual characters based on real-world locations detected via smartphones.