BANGKOK (Reuters) - Thailand on Thursday raised its COVID-19 alert level following rising infections driven by the spread of the Omicron variant of the coronavirus, a senior health official said.

       The change, from level three to four, sets a pretext for possible measures that could follow, such as closing high-risk areas and placing restrictions on domestic travel or public gatherings.

       "Thailand has entered a new wave of infections, where new cases will be rising fast," said Kiattiphum Wongrajit, permanent secretary of the health ministry.

       "Level four means we may close high-risk places and announce more measures."

       The move comes amid a sharp rise in daily infections since the beginning of the year.

       Thailand reported 5,775 new cases on Thursday, a 48% rise on the previous day and nearly double the number on Jan. 1.

       The Southeast Asian country has vaccinated about 69.1% of an estimated 72 million people living in the country with two doses, but only 10.9% have received booster shots.

       (Reporting by Panarat Thepgumpanat; Writing by Patpicha Tanakasempipat; Editing by Ed Davies)