South Korea has confirmed 536 more cases of four major contagious variants of the new coronavirus over the past week, including 374 cases of the highly transmissible delta variant, health authorities said Tuesday.

The caseload of such infections reached 3,353 here, with the number of delta cases first reported in India tallied at 790, according to the Korea Disease Control and Prevention Agency (KDCA).

Of the newly confirmed variant cases over the cited period, there were 395 local infections and 141 imported cases, the KDCA said.

Health authorities said the country will witness more cases of the highly transmissible delta variant down the road.

The rate of delta variant cases detected through a gene analysis came to 23.3 percent over the past one week, with 26.6 percent reported in the wider capital area, the KDCA said.

The steady rise in variant cases in the wider Seoul area poses a threat to the country's virus battle currently dogged by a spike in new cases and its inoculation campaign.

On Tuesday, the country added 1,150 new COVID-19 cases, rising by more than 1,000 for the seventh consecutive day, as worries ran high over a further uptick in new infections.

A total of 15.6 million people, or 30.4 percent of the country's population, have received their first shots of COVID-19 vaccines, remaining almost unchanged from 29.8 percent tallied at end-June.

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)