Some mourners chanted “Long live hip hop” and “God bless the king” as Charles passed by.
A woman holds up a Paddington bear toy to Charles; the fictional bear has been linked to the Queen since she was featured in a sketch alongside the character at the Platinum Jubilee celebration.
People have lined up for hours to see Queen Elizabeth II’s coffin since she began to lie down in Westminster Hall on Wednesday.
The government said the line was nearing full capacity on Saturday. At lunchtime on Saturday, the government’s queue tracker said the current wait time was 14 hours.
Earlier on Saturday, Charles III visited the Metropolitan Police headquarters in Lambeth, London, to thank the police and emergency services officers involved in planning and carrying out the incident following the death of the late Queen.
Deputy Assistant Commissioner Stuart Candy told a media briefing on Friday that the Queen’s funeral on Monday would be the “largest single policing event” ever for London’s Metropolitan Police.
The Queen’s grandchildren – including Princes William and Harry – are expected to hold a vigil in front of her coffin later on Saturday.
On Sunday, King Charles will host a reception for “heads of state and official dignitaries overseas” at Buckingham Palace ahead of the late Queen’s state funeral.
A source familiar with the matter told CNN that the Duke and Duchess of Sussex, Prince Harry and Meghan, received an invitation to that reception by mistake.
As a formal state occasion, the palace said the king would be accompanied only by members of the royal family. Sources told CNN they “imagined” an administrative error had occurred. As some media outlets reported, the couple was not “rejected” from the reception.
A spokesman for the Sussexes had no comment.