The police have received several complaints about a video showing a masked, knife-wielding man walking around Singapore and scaring people.
The video, posted on YouTube by Merlion TV last Monday, is inspired by last year's action horror film, The Purge. The film is set in a futuristic United States, where citizens are allowed to take part in an annual 12-hour free-for-all rampage.
A voice-over in the two-minute video said: "Any and all crime, including murder, will be legal for 12 continuous hours. May God be with you all."
In a Facebook post yesterday, the police said they have advised the video's producer on the possible consequences of staging such pranks, "which may generate unnecessary alarm, fear and panic in the community".
They also advised the public to refrain from such activities.
The video has since garnered 161,500 views and 200 comments. It has also been posted on citizen journalism website Stomp, where it has received over 82,400 views.
A post on Merlion TV's YouTube page read: "Halloween is around the corner, and the MerlionTV crew decided to do a similar purge movie scene in one of the safest country in the world - SINGAPORE! Let's see how they react to it," it said.
When contacted, MerlionTV - a content creator group - said via e-mail that the people in the video were notified that the scare was a Halloween prank and "no harm was intended". A spokesman said the people "laughed it off afterwards".
The video, which was filmed in mid-October, has attracted mixed comments. Some found it "awesome", while others warned that such pranksters may get into trouble.
One viewer, Cheng Ann Ang, said: "I know some people might find this hilarious and we should all chill... but seriously, this prank could potentially be dangerous."