SEOUL (Reuters) - South Korea's daily record of coronavirus cases reached a fresh high on Thursday, as authorities halted quarantine exemptions for fully vaccinated inbound travellers for two weeks in a bid to fend off the Omicron variant.

       The Korea Disease Control and Prevention Agency (KDCA) reported 5,266 cases for Wednesday, a day after the daily tally rose above 5,000 for the first time amid concerns over a sharp rise in patients with severe symptoms.

       South Korea will require a 10-day quarantine for all inbound travellers for two weeks starting Friday, halting exemptions given earlier to fully vaccinated people, the KDCA said.

       The measure came after South Korea confirmed its first five cases of the Omicron variant late on Wednesday, including a fully vaccinated couple who arrived last week from Nigeria, followed by two of their family members and a friend.

       The country has fully inoculated nearly 92% of adults and is now focusing on vaccinating children and a booster programme, but experts have warned that cases could continue to rise due in part to the spread of the potentially more transmissible variant.

       Total infections rose to 457,612, with 3,705 deaths.

       (Reporting by Hyonhee Shin; Editing by Richard Pullin)