Bahrain will suspend dine-in services at restaurants and cafes and move public and private schools to remote learning for three weeks to contain the spread of the coronavirus, the health ministry said.
It said it had detected a new variant of coronavirus in a number of cases, without specifying which kind.
The new lockdown measures will come into effect on Sunday.
There has been an uptick in coronavirus cases in the Gulf kingdom since December. The country registered 459 new cases on Wednesday, adding to a total of nearly 100,000 since the start of the pandemic, with 370 deaths.
The small island state has the third highest rate of vaccinations per capita in the world so far, according to the Our World in Data website, which is run by an Oxford University research programme.
Bahrain offers its citizens either the Pfizer/BioNTech vaccine or one manufactured by Chinese state-backed pharmaceutical giant Sinopharm free of charge.
The kingdom also approved the AstraZeneca COVID-19 vaccine on Monday for emergency use.
Hamas officials have arrived in Egypt on Sunday ahead of talks with Israel planned for Monday that the US hopes will lead to a halt in fighting and the freeing of hostages in Gaza, with Washington's top diplomat saying the next days are critical.
US forces hit another vessel allegedly carrying illegal drugs off the coast of Venezuela on Saturday evening, President Donald Trump said on Sunday, adding that they would also start looking at drug trafficking occurring on land.
The death toll from the collapse of an Islamic boarding school in Indonesia last week jumped to at least 49 people as rescuers have cleared nearly all of the debris, the country's disaster mitigation agency said in a statement handed out on Monday.
GCC Secretary-General Jasem Mohamed Al-Budaiwi has welcomed the steps taken by Hamas in response to US President Donald Trump's Gaza proposal while stressing on the importance of strengthening Gulf integration to confront accelerating global changes.
Israeli planes and tanks pounded areas across the Gaza Strip overnight and on Sunday, destroying several residential buildings, witnesses said, as Palestinians desperately awaited implementation of a US plan to end the war.