Three American service members and a dependent have tested positive for the new coronavirus upon arrival in South Korea this month, the US Forces Korea (USFK) said Monday.

While two of the service members tested positive on their first mandatory COVID-19 test upon arrival at Osan Air Base in Pyeongtaek, south of Seoul, the other service member and the dependent tested positive on their second test required to exit the two-week quarantine, according to the US military.

They all arrived here on US government chartered flights.

The latest cases brought the total number of USFK-related infections to 231, most of whom tested positive upon their arrivals here.

"Despite the recent confirmed cases, USFK remains at a high level of readiness with less than 1 percent of its active duty service members currently confirmed positive with COVID-19," it said in a release.

The announcement came as USFK eased anti-virus restrictions for its personnel in the greater Seoul area in step with the South Korean government's recent lowering of its social distancing level.

As of 4 p.m., all USFK members were allowed to dine at restaurants and conduct off-base activities.

The US military lowered the Health Protection Condition (HPCON) level by one notch to the second-lowest level of "Bravo" from "Charlie" for most parts of the country last month, but had kept stricter rules for Area II, defined as the Seoul metropolitan area, including the western city of Incheon.

All USFK personnel are still banned from visiting clubs, bars and other adult-only establishments across the country until further notice.

On Monday, South Korea reported 76 cases of the new coronavirus, raising the total caseload to 25,275. (Yonhap)