Tourist attraction Merlion Park has become a talking point after a group of people, believed to be mainly Malaysians, gathered there for a protest Wednesday night.
Police are now investigating five people believed to have organised the activity.
In a media statement sent to inSing, the police said: “While foreigners, including Malaysians, are allowed to work or live here, they have to abide by our laws. They should not import issues from their own countries into Singapore which can disturb public order, as there can be groups with opposing views.
“The authorities will act firmly, and those who break the law will face action which could include termination of their visa or work passes.”
Police stress that conducting an outdoor protest without a police permit is illegal in Singapore.
Pictures of the crowd of about 100 at the Esplanade area started surfacing on online forums and social media last night.
Malaysia just held its general election on Sunday 5 May.
Its ruling Barisan Nasional coalition remained in power to govern the country, amid allegations from the opposition that the election was tainted by cheating and fraud, such as suspected foreigners being recruited to vote.
Opposition leader Anwar Ibrahim held a mass rally in Kuala Lumpur last night to protest against the election results. Malaysian media have reported that he wants to organise a series of protest gatherings around the country.
His supporters were told to wear black to symbolise that it is “a black day for democracy”.
In Singapore, the crowd at Merlion Park also turned up in black. They are believed to have gathered there after learning about it via Facebook, and there were apparently similar gatherings in a few other countries last night, such as in Australia and Taiwan.
SHOUTS OF 'UBAH'
From 10pm to 11pm, the atmosphere there was mostly laidback, with people spending time taking photos of themselves and their placards.
Now and then, there would be shouts of “ubah”, which is Malay for “change”.
There were also signs showing the numbers “1758” – when read in Mandarin, it sounds like “Together, we 'ubah'”.
Later, some plainclothes policemen arrived.
In its statement, police said that they received a call at 9.50pm Wednesday informing them of an outdoor protest at Merlion Park.
At the scene, officers advised the group that what they were doing is illegal in Singapore, and they “dispersed peacefully”.