Changi Airport will open up further to transit passengers, with Jetstar Asia announcing yesterday that those on its flights from six South-east Asian cities will be able to transit via Singapore to other destinations from Dec 1.

It is the fourth airline allowed to operate such transit flights after the three airlines under the Singapore Airlines (SIA) Group - SIA, Scoot and SilkAir - began doing so in August.

Such a move is expected to give traffic at Changi Airport a small boost, although aviation experts have said that demand for these flights will likely remain low, given continued restrictions on international travel and the lack of a meaningful travel bubble in South-east Asia.

The transit flights apply to Jetstar Asia passengers departing from Bangkok, Ho Chi Minh City, Jakarta, Kuala Lumpur, Penang and Phnom Penh.

Those transiting will have to wear a wristband throughout their journey so they can be identified by airport and airline staff.

Jetstar Asia said they will, as far as possible, be kept separate from other passengers by being seated together near the front of the aircraft.

They will disembark from the planes first and board last, and will be kept at a transit holding area or hotel during their time in Singapore, which must not exceed 48 hours.

But those arriving from Vietnam will be exempted from these regulations as it is one of the countries Singapore has decided to unilaterally lift border restrictions.

Singapore did so last month after assessing that visitors from Vietnam were unlikely to have the coronavirus due to the country's public health surveillance system and low infection rates.

Visitors from Vietnam are able to go about their activities in Singapore after a negative Covid-19 swab test upon arrival here and need not serve a stay-home notice.

The transit flights are a "positive step in the airline's recovery", said Jetstar Asia chief executive officer Bara Pasupathi.

The budget carrier had cut a quarter of its Singapore-based workforce in July and retired five of its aircraft.

It now has a total fleet of 13 aircraft that fly to nine cities.

At its peak, transfer and transit passengers accounted for about a third of Changi's passenger traffic. Current levels remain far short of that.