Queen Elizabeth, 95, has tested positive for COVID and is experiencing mild symptoms, Buckingham Palace said on Sunday.
"The queen has today tested positive for COVID," the Palace said. "Her Majesty is experiencing mild cold like symptoms but expects to continue light duties at Windsor over the coming week.
"She will continue to receive medical attention and will follow all appropriate guidelines."
Charles, 73, the heir to the throne, earlier this month pulled out of an event after contracting coronavirus for a second time. A palace source said he had met the queen just days before.
The health of the queen, the world's oldest and longest-reigning monarch, has been in the spotlight since she spent a night in hospital last October for an unspecified ailment and then was advised by her doctors to rest.
Elizabeth on Wednesday quipped to members of the royal household that she could not move much as she carried out her first in-person engagement since Charles tested positive.
An Air India plane crashed at the airport in India's western city of Ahmedabad, television channels reported on Thursday, without specifying whether there were any fatalities.
The United Nations General Assembly will vote on Thursday on a draft resolution that demands an immediate, unconditional and permanent ceasefire in the war in Gaza after the US vetoed a similar effort in the Security Council last week.
Israel's parliament rejected early on Thursday a preliminary vote to dissolve itself, the Knesset said in a statement, after an agreement was reached regarding a dispute over conscription.
US troops in Los Angeles are authorised to detain people until police can arrest them, their commanding officer said on Wednesday, as hundreds of Marines prepared to move into a city rocked by protests over President Donald Trump's immigration raids.
The Arab League has welcomed the sanctions imposed on two Israeli far-right ministers, saying the move is a step towards accountability for "instigated violence" and "contributing to settler attacks on Palestinians".