One more service member of South Korea's Cheonghae anti-piracy unit off the coast of Africa has tested positive for the coronavirus, bringing the total caseload there to seven, the defense ministry said Saturday.

Earlier this week, six service members of the 300-strong unit aboard the 4,400-ton Munmu the Great destroyer were confirmed to have been infected, and the authorities conducted virus tests on all other crewmembers.

Fears of a mass infection have grown as around 80 others have shown symptoms consistent with COVID-19.

The newly confirmed service member showed symptoms of pneumonia and has been under treatment at a local hospital where he underwent a virus test, the ministry said.

The test results for all other personnel were initially supposed to be available by Saturday morning, but there appeared to have been some delays in analyzing the data at local medical centers, according to officials.

Multiple sources from the military, meanwhile, said 49 of the 50 service members tested positive through rapid antigen tests, which were conducted before receiving polymerase chain reaction (PCR) examinations.

While rapid antigen tests tend to be less accurate compared with PCR examinations, experts say it is still highly likely that those who tested positive are infected with COVID-19.

In addition to the man, 11 other crew members have been in a hospital for treatment, and others are in isolation on the vessel, they added.

The crewmembers have been kept in close proximity to each other while staying together for months aboard the ship. None of the Cheonghae members have been vaccinated, as they left South Korea in February just before the country began its inoculation campaign.

Contact tracing is under way, but the infections appeared to have begun after the vessel was docked at a nearby port for days late last month to load supplies, according to the officials.

South Korea is preparing to send KC-330 Cygnus multi-role aerial tankers there to bring home all the crewmembers, according to the defense ministry. In a message sent to families of the crew members, the head of the unit said all the crew members are expected to be airlifted home sometime next week.

It is also working on a plan to fly separate aircraft equipped with medical equipment to airlift those with symptoms in preparation of contingencies, the officials added. (Yonhap)