The US Forces Korea is facing criticism over a dance party held at one of its bases last week at which participants did not wear face masks amid South Korea's heightened social distancing scheme to stem the resurgence of new coronavirus cases.

The party took place at Flightline Tap Room at Camp Humphreys in Pyeongtaek, south of Seoul, on Friday, with dozens of people dancing side by side without wearing masks, according to officials.

On the same day, South Korea's daily number of new COVID-19 cases reached a near nine-month high of 629, with authorities urging citizens to cancel non-vital face-to-face gatherings.

The Seoul government has requested the US military to follow antivirus measures. The US military said Monday that the bar was "closed effective immediately, per command directive." 

"The facility has been closed, and we are looking into the matter," a USFK official said.

Michael Tremblay, garrison commander of Camp Humphreys, and John Gonzales, 51st Fighter Wing commander, have apologized over the incident during their separate phone talks with Pyeongtaek Mayor Jung Jang-seon, the city government said.

The US military is considering additional measures, including expanded coronavirus testing of servicemembers and shutting down more entertainment facilities, according to the city and Seoul's foreign ministry.

Under the USFK antivirus rules currently in place, its members are ordered to keep a minimum 1 meter of social distance and to wear masks when such separation is impossible. It also orders its personnel to avoid large crowds and to follow all South Korean rules, directives and laws.

When the party took place, the Seoul metropolitan area was put under social distancing Level 2 -- the third-highest among the country's five-tier virus alert system -- with indoor exercises practiced by groups and year-end parties hosted by hotels banned.

USFK also came under fire in July over its soldiers' unruly Fourth of July celebrations after dozens of complaints were filed in the southeastern city of Busan over wild and dangerous acts by foreigners wearing no face masks.

Following the incident, the US military expressed regret and vowed to take appropriate disciplinary action against those involved.

As of Monday, 408 USFK-affiliated individuals have tested positive for the new virus.

South Korea reported 594 new infections Tuesday, raising the total caseload to 38,755. (Yonhap)