Twenty-two American service members have tested positive for the new coronavirus upon arrival in South Korea from the United States, the US Forces Korea (USFK) said Tuesday.

Of them, 18 arrived at Osan Air Base in Pyeongtaek, south of Seoul, on US government chartered flights from the US, and the remaining four arrived at Incheon International Airport, west of Seoul, on commercial flights from their home country between Sept. 25 and Oct. 9, according to the US military.

Half of them tested positive on their first mandatory COVID-19 test prior to entering quarantine, and the other 11 were confirmed to have been infected on their second test required to exit quarantine.

They were transferred to an isolation facility designated for COVID-19 patients at Camp Humphreys and Osan Air Base in Pyeongtaek and Kunsan Air Base located in the western city of Gunsan, USFK said.

"Thorough cleaning of all transportation assets and quarantine rooms has been completed," USFK said in a statement. "None of the new arrivals have interacted with anyone residing within USFK installations or the local community."

The latest cases brought the total number of USFK-related infections to 225, most of whom tested positive upon their arrivals here.

Starting on Aug. 30, the US Department of Army has required all American soldiers, family members and other related civilians to have a negative test result for the new coronavirus prior to their departure for South Korea.

But the requirement does not apply to service members from the Navy, the Air Force and the Marine Corps. (Yonhap)