Several more airlines have received approval from the Civil Aviation Authority of Singapore (CAAS) to stop over at Changi Airport with passengers who are en route to other destinations.
At least three airlines - German carrier Lufthansa, Swiss International Air Lines and Garuda Indonesia - resumed ferrying transit passengers this month, according to checks by The Straits Times.
On its website, Singapore Airlines says it has agreements with Air France and KLM Royal Dutch Airlines to let their customers transit through Changi from approved cities to destinations that SIA and SilkAir fly to.
The move marks another small step forward in reviving the Republic's air hub, which has been battered by travel restrictions amid the Covid-19 pandemic.
While Singapore has reopened its borders to transit passenger traffic since June last year, only the three airlines under the SIA Group were allowed to ferry such passengers until end-November last year. Local budget carrier Jetstar Asia received approval to resume flying in transit passengers in December.
In response to queries from The Straits Times, CAAS confirmed that several foreign airlines have since been allowed to operate transfer routes through Changi. It declined to comment on which carriers have received approval, citing commercial sensitivities.
A spokesman added: "CAAS evaluates airlines' applications to operate transfer routes taking into consideration the measures that the airlines propose to put in place to manage the risk of transmission at Changi Airport.
"Approval will be given only when we have ensured that the safety and well-being of passengers and airport staff are safeguarded."
Passengers will have to remain in designated facilities in the transit area. But those who come from places that Singapore have unilaterally opened its borders to, such as China and Vietnam, are exempted from this rule.
All passengers also have to take precautions such as wearing masks and practising safe distancing. Airport staff who interact with them will wear protective equipment, including masks, face shields, goggles and even medical gowns where appropriate.
Lufthansa said on its website that its passengers have been able to stop over at Changi since Jan 4, provided they are transferring to flights operated by SIA and its regional arm SilkAir.
It said it has received regulatory approval to fly transit passengers from all cities it serves in Europe and the United States through Singapore to around the region, and vice versa.
The exception is Britain, which is allowed only as a destination country but not the country of origin.
Similar procedures apply for Swiss International Air Lines, which is owned by Lufthansa.
Meanwhile, Garuda said its transit passengers have been allowed to fly to Changi from Jakarta, Surabaya and Denpasar since Jan 1. Similarly, they can transfer only to flights by SIA and SilkAir.
Mr Mohshin Aziz, director of the Pangolin Aviation Recovery Fund, said airlines like Qantas that use Singapore to transit to Australia and New Zealand could be the next in line.
He added: "The impact will not be financially significant because it's only a handful of airlines. But it tells you that Changi is moving to gear one of recovery. It's no longer moving backwards or stuck on neutral, but taking baby steps forward."