South Korean health officials have approved Pfizer's Covid-19 vaccine for children aged 5 to 11, expanding the country's immunisation programme in the face of a massive omicron outbreak that is driving up hospitalisations and deaths.

The Korea Disease Control and Prevention Agency didn't immediately say when vaccinations for this age group would begin, AP reported.

The KDCA reported a record 171,452 new virus cases, nearly a 40-fold increase from levels in mid-January when Omicron first emerged as the countrys dominant strain. The 99 new deaths were the highest daily tally since Dec 31, when the country was grappling with a Delta-driven surge that buckled hospital systems.