SINGAPORE - One of two runways at Singapore's main airport closed for short periods on Tuesday and Wednesday because of "confirmed sightings of unauthorised drone flying", the aviation regulator said.

Around 37 scheduled departures and arrivals were delayed at the popular Changi airport, with one scheduled arrival diverted to Kuala Lumpur, Civil Aviation Authority of Singapore (CAAS) said in a statement.

CAAS said a multi-agency team including airport staff, the armed forces and police was activated to try to track down the source of the intrusion.

The regulator did not specify if more than one drone was involved.

Offenders could face a fine not exceeding S$20,000 (US$14,600) or a jail term of up to a year, or both, CAAS said.

In December, drone sightings caused three days of travel chaos at London's Gatwick airport, resulting in the cancellation or diversion of about 1,000 flights at an estimated cost of more than 50 million pounds ($63 million).

(Reporting by Jamie Freed; Editing by Nick Macfie) ((Jamie.Freed@thomsonreuters.com; +65 6318 4789;))