Singapore Airlines crew members at Changi International Airport in Singapore on Oct. 24, 2020.Roslan Rahman | AFP | Getty ImagesSINGAPORE — Singapore and Hong Kong will go ahead with their air travel arrangements on Sunday as planned, but there will be additional precautionary measures imposed as new coronavirus cases in Hong Kong rise.The Civil Aviation Authority of Singapore announced Saturday that all arriving passengers from Hong Kong will now be required to take an additional Covid-19 Polymerase Chain Reaction (PCR) test upon arrival.They will also need to self-isolate in their place of residence — be it a hotel or home — as they wait for the results which will take about six to eight hours, the aviation authority said.To be clear, all passengers from Hong Kong under the air travel bubble agreement were already required to take a pre-departure Covid-19 PCR test and obtain a negative test result before departing for Singapore.”As mentioned, travellers will now undergo a further on-arrival COVID-19 PCR test,” according to the latest release from CAAS.The initial air travel bubble agreement announced on Nov. 11 did not require any isolation of passengers from Hong Kong upon arrival.Hong Kong’s ‘new wave’Hong Kong reported Friday that the number of new daily cases rose to 26, and most of them were local infections.”We have probably entered into a new wave of cases,” the city’s Secretary for Food and Health Sophia Chan said in a press briefing on Friday, citing experts from the Centre for Health Protection.She said the situation was “severe” and urged citizens to stop all unnecessary gatherings.The government met late Friday to finalize other contingency measures aimed at stemming the spread of the virus, and will not rule out more stringent restrictions, Chief Executive Carrie Lam said in a Facebook post.Hong Kong imposed new restrictions on Saturday, including the banning of clubs and party rooms, as well as prohibiting live performances and dancing in bars and pubs. The government announced earlier that primary schools will be suspended for two weeks from Monday.The Singapore and Hong Kong health authorities are in close contact and monitoring the situation.Civil Aviation Authority of SingaporeTravel authorities from both sides have always said the deal will be suspended if the Covid-19 situation in either city deteriorates.The Hong Kong-Singapore air travel bubble agreement is due to start on Nov. 22 with a single flight daily into each city, limited to a maximum of 200 passengers per flight. The number of flights will increase only if the spread of Covid-19 in both cities remains under control.Singapore’s aviation authority reiterated on Saturday that the air travel bubble “will be suspended if the seven-day moving average of unlinked cases exceeds five per day.””The figure for Hong Kong is currently at 2.14,” CAAS said. “The threshold will be exceeded if there are more than 22 unlinked cases in Hong Kong over the next three days. This will trigger a two-day notice period, after which suspension will come into effect.””The Singapore and Hong Kong health authorities are in close contact and monitoring the situation,” the aviation authority said.