Hundreds of Singaporeans angered by the walkover victory of their first female president held a "silent sit-in" in a park Saturday in a rare political protest denouncing the lack of an election.

Halimah Yacob, a former speaker of parliament from the Malay Muslim minority, was sworn in Thursday without a vote after two potential rivals were disqualified from running.

The protest followed outrage on social media over what critics say was the engineered victory of an establishment figure.

While the role is largely ceremonial, the president has veto powers on key government appointments and safeguards the country's substantial financial reserves.

Social activist Gilbert Goh, who organised the protest, said it was to highlight the "sense of betrayal" Singaporeans felt after being robbed of a chance to vote in their head of state.

"We are not against (the president)... We are against the system. We are against the process against the right to exercise our democratic vote," Goh told media after the protest.

Scores of Singaporeans dressed in black milled around the park, some holding up signs calling the presidency a "(S)election", while others wore T-shirts emblazoned with the hashtag "not my president", which first gained popularity among Americans unhappy with the victory of Donald Trump.

Organisers said about 2,000 people showed up to the protest but an AFP reporter counted about 800.

Goh said an earlier rally was cancelled because a special police permit was needed since the event would have touched on race.

Sedition laws in Singapore make it an offence to promote hostility between different races or classes in the multiracial society, which is mainly ethnic Chinese with large Malay and Indian minorities, but critics say this stifles free speech.

Authorities decided to allow only candidates from the Malay community in the presidential election to foster harmony in the city-state of 5.5 million people which is dominated by ethnic Chinese, and give more opportunities to minorities.

Halimah is the first Malay president of Singapore for almost five decades. The last was Yusof Ishak, president from 1965 to 1970, the first years of the city-state's independence.

Source: AFP