Twenty-one Malaysians were arrested in Singapore on Saturday for staging an illegal protest following the disputed elections in their neighbouring homeland, the city-state's police said.
The Singapore Police Force (SPF) said in a statement that "while foreigners are allowed to work or live here, they have to abide by our laws".
"They should not import their domestic issues from their countries into Singapore and conduct activities which can disturb public order, as there can be groups with opposing views. Those who break the law will be seriously dealt with."
A police spokesman told AFP that the Malaysians were held under the Public Order Act, under which organisers of illegal protests can be jailed up to six months or fined Sg$10,000 ($8,100). They can also be both jailed and fined.
Participants in illegal protests can be fined up to Sg$5,000. Foreigners jailed in Singapore are normally deported after serving their sentences.
The Malaysians were arrested at Merlion Park, a popular tourist attraction along Singapore's Marina Bay promenade, for staging a protest "despite repeated police advisories" against such gatherings, the SPF statement said.
The arrests came three days after an estimated 100 Malaysians gathered at the same spot in conjunction with a mammoth rally in Malaysia's capital Kuala Lumpur by the opposition, which claims it was robbed of victory in the May 5 parliamentary elections through fraud.
Nine of the participants in Wednesday's protest in Singapore received police warnings.
"Their work and visit passes in Singapore are being reviewed by the authorities. Their employers will be informed of this. Further investigations are ongoing," according to an SPF statement on Friday.
The Malaysian opposition, led by former deputy prime minister Anwar Ibrahim, has called for a wave of protests after the ruling coalition was returned to power despite receiving less than 50 percent of votes cast.
Singapore was ejected from the Malaysian federation in 1965 after a brief union between the two former British colonies, but they are bound by strong economic, political, cultural and family links.