Asia's busiest airport hub has been disrupted for the second time in a week by rogue drone pilots, Singapore authorities have confirmed.
Around 18 flights were delayed yesterday and a further seven diverted, with Singapore's Civil Aviation Authority (CAAS) citing "unauthorised drone activities" as part of the problem.
The window of delay was around an hour.
Flights resumed yesterday evening, with those responsible for the errant drones unaccounted for and still at large.
It is unclear if the incident was connected to another drone sighting, last Wednesday which disrupted 37 flights.
The CAAS said "investigations were ongoing."
"Members of the public are reminded that the authorities take a serious view of errant operations of unmanned aircraft which may pose threats to aviation or endanger the personal safety of others," said a statement from the Singapore CAA.
Offenders could face fines of up to SIN$20,000 ($1112) and a maximum of 12 months in prison if found guilty.
The Straits Times in Singapore said that local hobbyists are unlikely to be behind the drone sightings. Local recreational drone pilots were quick to denounce the pilots.
"I would think he is either very new to flying drones or a foreigner who is not aware of the regulations," Mr Alvin Yeoh, a spokesperson for the Multirotor Association of Singapore told The Times.
However, an uninformed tourist or hobbyist is unlikely to be behind the scare.
It was also reported by The Times that the drones sighted were not recreational models, and not readily available to consumers.
This has led to speculation that the disruptions may have been intentional.
Drones have previously been used to disrupt busy airports in Europe. In December 140,000 travellers were affected after rogue drones grounded flights at London's Gatwick and Heathrow airports.
As the London airports were left with 1000 cancelled flights and no leads as to who the drone pilots were, drone defence has become a big concern for airports.
With the latest series of nuisance attacks in Singapore, it appears the threat of rogue drone pilots has become a pandemic - affecting passengers and operators around the world.