SEOUL, South Korea >> South Korea saw its deadliest day of the pandemic on Saturday, reporting 112 fatalities in the latest 24-hour period, as it grapples with a wave of coronavirus infections driven by the fast-moving omicron variant.

Health workers diagnosed 166,209 new cases, which came close to Wednesday’s one-day record of 171,451 and represented more than a 37-fold increase from daily levels in mid-January, when omicron first emerged as the country’s dominant strain.

Omicron has so far seemed less likely to cause serious illness or death than the delta strain that hit the country hard in December and early January. But hospitalizations and deaths are beginning to creep up amid a growing outbreak that is stretching worn-out health and public workers.

More than 640 virus patients were in serious or critical condition, the Korea Disease Control and Prevention Agency said, compared to around 200-300 in mid-February. The Health Ministry said about 44% of the country’s intensive care units designated for COVID-19 patients are occupied.

Prime Minister Kim Boo-kyum, Seoul’s No. 2 official behind President Moon Jae-in, said Friday that health authorities anticipate the omicron wave will peak sometime in mid-March, when the country may see daily cases of around 250,000. There are concerns that transmissions could worsen with schools beginning new semesters in March and also because of political rallies ahead of the March 9 presidential election.

More than 86% of the country’s population of more than 51 million have been fully vaccinated and around 60% have received booster shots. The country has been rolling out fourth vaccination shots to people at nursery homes and long-term care settings to protect them from the omicron surge. Officials on Wednesday approved Pfizer’s COVID-19 vaccine for children aged 5 to 11 and plan to announce the rollout for that age group in March.