The UK monarch has worn a face mask in public for the first time as she visited the grave of the Unknown Warrior to mark 100 years since his burial.

The visit to Westminster Abbey was her first public engagement in London since March, Sky News reports.

A royal aide said Wednesday's service was "deeply personal" for the Queen, who was married there in 1947, and she left flowers based on her wedding bouquet on the grave.

The Queen's mask was black and edged with white and is thought to have been made by Angela Kelly, who designs many of the monarch's outfits. However, Buckingham Palace has not commented.

Prince William and Prince Charles are among the royals who have worn a mask at official events in recent months.

In October, the Queen was criticized by some for not wearing a face covering when she visited the Porton Down defence laboratory with the Duke of Cambridge.

The visit to Westminster Abbey comes as Remembrance Sunday events are significantly scaled back due to coronavirus, with the public urged to take part in "remote acts of remembrance" such as marking the silence from their doorstep.

The Cenotaph ceremony in London has been closed to the public for the first time, with the large march-past of veterans unable to go ahead.

However, the Queen, the Prince of Wales and the Duke of Cambridge are still expected to attend.

This Sunday marks a century of the famous memorial on Whitehall - and 100 years since the Unknown Warrior's remains were buried among the country's monarchs at Westminster Abbey.

The Cenotaph ceremony in London has been closed to the public for the first time, with the large march-past of veterans unable to go ahead.

However, the Queen, the Prince of Wales and the Duke of Cambridge are still expected to attend.

This Sunday marks a century of the famous memorial on Whitehall - and 100 years since the Unknown Warrior's remains were buried among the country's monarchs at Westminster Abbey.-Photos: Sky News

The Queen's Equerry, Lieutenant Colonel Nana Kofi Twumasi-Ankrah, places a bouquet on the grave of the Unknown Warrior.

UK monarch dons face mask for first time in public