SINGAPORE - Several foreigners have been questioned by the police after they attended a candlelight vigil at Hong Lim Park held on Wednesday evening in support of pro-democracy demonstrators in Hong Kong.

A police spokesman, responding to questions from The Straits Times, said the foreigners were "currently assisting with investigations into offences under the Public Order Act".

The spokesman did not provide details on what the foreigners were being questioned about, or the number who were being questioned, but said that no arrests had been made.

Under the terms and conditions for the use of Speakers' Corner at Hong Lim Park, which comes under the jurisdiction of NParks, only Singaporeans and permanent residents can take part in demonstrations held there.

Foreigners cannot participate unless they have a permit from the police. Those who organise "assemblies and processions" involving foreigners, are also required to get a permit.

Otherwise foreigners can observe events but cannot, for example, chant slogans, wave flags and placards, or give speeches.

The police spokesman said: "The Speakers' Corner is a designated site for Singapore Citizens to speak freely on issues as long as they do not touch on racial or religious matters ... 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."

Hongkongers were among the several hundred people who turned up for the vigil on Wednesday evening.

When the event started, the crowd sang "Under A Vast Sky", a Cantonese song by Hong Kong rock band Beyond that has become the protest's unofficial anthem.

They also sang along to other songs , lit candles and wrote messages of support for people in Hong Kong, who have taken to the streets to push for universal suffrage.

Many at Wednesday's gathering wore black with yellow ribbons pinned on their garb, both symbols of the Hong Kong protest.

Mr Jolovan Wham, 34, one of the event's organisers, told The Straits Times that he was not in touch with the foreigners who were questioned by the police, and did not know who they were.

He also said that he had not been questioned by the police.

Before the event began, police officers reminded him to comply with the rules and regulations pertaining to the use of the area.

Mr Wham, 34, and co-organiser Rachel Zeng, 31, had provided a link to these rules on the event's Facebook page when it was set up.

They also wrote: "If you don't have a permit, you can come and 'observe'. Observing a protest or a demonstration is legal. How you choose to 'observe' is entirely up to you. We can't stop you and we shouldn't have to!"

Ms Zeng, an early childhood educator, said she had organised the vigil as she wanted to stand in solidarity with the protesters in Hong Kong and give them a "morale boost". She was also against the actions of the police in Hong Kong, she added.

The demonstrations in Hong Kong are against China's decision to screen candidates running in the Special Administrative Region's elections in future.