Global disease experts say little is known about China's experience with long-term COVID effects thought to have afflicted millions with debilitating fatigue, brain fog and other symptoms
It also ordered a halt on the unloading of goods from the ship that arrived at the outer anchorage with 46,300 tonnes of DAP fertiliser on Aug 12.
The ship, Serene Juniper, reported that several of its sailors had developed COVID symptoms and seven had fever, Dr Nurul Absar, assistant health officer of the port, said on Sunday.
Samples from the sailors were sent for test and further measures will be taken after the reports arrive in the night.