Singapore has made it mandatory for residents to present a negative Covid-19 PCR test report not older than 72 hours prior to their departure, starting 29 May.According to a ministry of health statement, all Singaporeans and permanent residents (PRs) will only be allowed to board flights to Singapore if they furnish a polymerase chain reaction (PCR) test report."All travellers will also be required to present their valid Covid-19 PCR test result at the air, sea and land checkpoints when they arrive in Singapore," the ministry said.An exception to the rules is those residents who were in lower-risk countries and regions in the last 21 days.