Singapore is hosting the Apec summit later this year
Singapore has warned foreign protesters against trying to disrupt an Asia-Pacific summit in November due to be attended by US President Barack Obama.
The city-state's home affairs minister, Wong Kan Seng, said the threat from terrorists and anarchists was real.
He was speaking in the week Singapore passed a new Public Order Act which bars all public assembly without prior police permission.
Singapore had previously banned any gathering of five or more people.
Mr Wong, who is also a deputy prime minister, said the November Apec summit "may attract terrorist interest".
"This is why we have to be very firm during that period with protestors and anarchists who may engage in acts of violence, or deliberately cause law and order problems," he said in remarks carried on his ministry's website on Thursday
On Monday, Singapore tightened its already strict rules on public assembly, placing more restrictions on protesters and giving police the power to intervene to prevent a political gathering from growing.
The only area where people may gather to express a view is the government-run Speakers' Corner.
Outside that, any public assembly will require a police permit, regardless of the number of people involved.
"Unlawful activities will not be tolerated. We will implement the law firmly," said Mr Wong.
His comments came after Thailand suffered the embarrassment of having to cancel a summit of the Association of South East Asian Nations due to public protests.
Singapore's leaders say tough laws against dissent and other political activity are necessary to ensure the stability which has helped the city-state achieve economic success.