South Korea has confirmed 3,091 more cases of four major contagious variants of the new coronavirus over the past week, including 3,070 of the highly transmissible delta variant, health authorities said Tuesday.

The caseload of such infections reached 23,388 here, with the number of delta cases, first reported in India, tallied at 19,951, according to the Korea Disease Control and Prevention Agency (KDCA).

The tally indicates the delta variant is becoming the dominant strain of COVID-19 here, making it more difficult for health authorities to curb the spread of the new coronavirus.

The KDCA also said it has detected three cases of the gamma variant, including an entrant from Argentina.

The delta variant is behind a recent spike in COVID-19 infections in Seoul and its neighboring areas, while showing signs of spreading much faster into the rest of the country.

Health authorities said the country will witness more cases of the variants down the road.

The rate of variant cases detected through gene analysis came to 97.3 percent over the past week, up from 94.8 percent reported a week earlier, the KDCA said.

The corresponding figure for the delta variant was 97 percent, up from 94.3 percent a week earlier, according to the health authorities.

On Tuesday, the country added 1,597 more COVID-19 cases, raising the total caseload to 263,374, the KDCA said.

To block the inflow of the new emerging strain from India, entrants from the country are mandatorily quarantined at state facilities for seven days before being put under self-quarantine, depending on the results of virus tests. (Yonhap)