South Korea has confirmed 20 more cases of contagious variants of the new coronavirus, bringing the total to 182, according to health authorities Monday amid concerns that the variants may worsen the country's virus battle.

The Korea Disease Control and Prevention Agency (KDCA) said the 20 people were confirmed to have been infected with three kinds of variants that are known to be more transmissible over the past week.

Of them, nine people were local infections, all South Korean nationals, and 11 were imported cases, the KDCA said.

When the latest virus cases are included, 154 cases are the Britain-originated variant.

The authorities have said they remain vigilant against the possibility that highly transmissible new variants from Britain, South Africa and Brazil could spark another uptick in virus cases here.

The recent emergence of several COVID-19 mutations has complicated the global fight against the pandemic because they are more transmissible than the original one.

South Korea has extended the ban on passenger flights arriving from Britain, which has been in place since Dec. 23, until Thursday to block the new virus variant that was first identified in Britain.

Also, all entrants, both foreigners and locals, have been required to present certificates of negative polymerase chain reaction (PCR) tests taken within 72 hours of their departure for South Korea since late February.

The country added 346 more COVID-19 cases Monday, returning to below 400, with the total caseload at 92,817, the KDCA said. (Yonhap)