The U.S. Forces Korea (USFK) said Monday that an additional 13 U.S. soldiers and two civilians in South Korea have tested positive for COVID-19.

The USFK said in a statement that 15 USFK-affiliated individuals were confirmed with COVID-19 after arriving in South Korea between January 21 and February 6.

Of them, two service members arrived at Osan Air Base on U.S. government-chartered flights from the United States on January 25 and February 3. The Osan Air Base is located in Pyeongtaek, 70 km south of Seoul.

The confirmed patients have been transferred to designated isolation facilities at the U.S. Army Garrison Humphreys and the Osan Air Base, both of which are located in Pyeongtaek, and the Kunsan Air Base in the southwestern city of Kunsan.

"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," the USFK said.

The total number of infections among the USFK-affiliated personnel rose to 721, according to the Yonhap news agency.