A Singapore Airlines (SIA) flight from San Francisco via Hong Kong received a bomb threat but arrived without incident in Singapore on Sunday, police said.
Police said in a statement that they conducted checks but nothing suspicious was found on the plane or on its passengers.
It did not say where and how the threat was made.
The city-state, a close US military and economic partner, raised its security alert level soon after the November 13 attacks by Islamic State militants in Paris which killed 130 people.
Singapore hosts the offices and production facilities of thousands of multinational corporations and is Southeast Asia’s main aviation hub.
Authorities in 2001 foiled a plot to bomb US and other foreign targets in Singapore and arrested several local Muslims suspected of links with regional militants.
Local newspaper Today said on its website that the SIA flight arrived around noon but passengers were only allowed to disembark one and a half hours later, with baggage release delayed further by security screening.
It quoted a passenger as saying that the plane was parked in a remote area in the airport before they were ferried by bus to the terminal.
A Turkish Airlines plane flying from New York to Istanbul was diverted to Canada on Sunday because of a bomb threat, but police said no explosives were found.