South Korea has confirmed 1,252 more cases of four major contagious variants of the new coronavirus over the past week, with the portion of the highly transmissible delta variant spiking, health authorities said Tuesday.

The country's total cases of four major variants stood at 4,605 as of Saturday, and of the variant cases newly identified between July 11 and 17, the delta variant accounted for 76 percent, or 951 cases, according to the Korea Disease Control and Prevention Agency (KDCA).

The delta variant, which was first found in India, was followed by the Britain-originated alpha variant with 297 and the beta and gamma variants with two each.

Of the newly confirmed variant cases over the cited period, there were 1,001 local infections and 251 imported cases.

The rate of variant COVID-19 cases detected through a gene analysis came to 52.6 percent over the past one week, sharply up from 44.1 percent a week earlier, the KDCA said.

In particular, the rate of the delta variant in domestic infections reached 33.9 percent, up from 23.3 percent a week earlier. Its portion was only 2.5 percent in the third week of June.

The KDCA said considering the pace of its spread, it is likely that the delta variant will be the most dominant COVID-19 variant in South Korea in upcoming weeks.

Of the confirmed variant cases, the alpha variant accounts for 2,702 cases, followed by the delta variant with 1,741 and the beta variant with 145, according to the KCDA. (Yonhap)