LONDON (AP) — All eight of Queen Elizabeth II’s grandchildren stood in silent vigil beside her coffin Saturday, capping another huge day in which thousands came to pay their respects. Mourners huddled in a line that snaked across London, enduring the city’s coldest night in months and waits that stretched up to 16 hours.

Authorities warned that more chilly weather was expected Saturday night. “Tonight’s forecast is cold. Warm clothing is recommended,” the ministry in charge of the line tweeted.

As US President Joe Biden and other world leaders and dignitaries flew into London ahead of the queen’s state funeral on Monday, a tide of people wanting to say goodbye streamed into Parliament’s Westminster Hall for another day Saturday. That’s where the queen’s coffin is lying in state, draped in her Royal Standard and capped with a diamond-studded crown.

The numbers of mourners have grown steadily since the public was first admitted on Wednesday, with a queue that snakes around Southwark Park and stretches for at least 5 miles (8 kilometres).

Honoring their patience, King Charles III and his eldest son Prince William made an unannounced visit Saturday to greet people waiting to file past Elizabeth’s coffin, shaking hands and thanking mourners in the queue near Lambeth Bridge.

Later, all the queen’s grandchildren stood by her coffin. William and Prince Harry, Charles’ sons, were joined by Princess Anne’s children, Zara Tindall and Peter Philips; Prince Andrew’s daughters, Princess Beatrice and Princess Eugenie; and the two children of Prince Edward – Lady Louise Windsor and James, Viscount Severn.

William, now the heir to the throne, stood, his head bowed, at the head of the coffin and Harry at the foot. Both princes, who are military veterans, were in uniform. Mourners continued to file past in silence.

Harry, who served in Afghanistan as a British army officer, wore civilian clothes earlier in the week as the queen’s coffin left Buckingham Palace because he is no longer a working member of the royal family. He and his wife Meghan quit royal duties and moved to the United States in 2020. The king, however, requested that both William and Harry wear their military uniforms at the Westminster Hall vigil.

Before the vigil, Princesses Beatrice and Eugenie issued a statement praising their “beloved grannie.”

“We, like many, thought you’d be here forever. And we all miss you terribly. You were our matriarch, our guide, our loving hand on our backs leading us through this world. You taught us so much and we will cherish those lessons and memories forever,” the sisters wrote.

People queuing to see the queen have been of all ages and come from all walks of life. Many bowed before the coffin or made a sign of the cross. Several veterans, their medals shining, offered sharp salutes. Some people wept. Others blew kisses. Many hugged one another as they stepped away, proud to have spent hours in line to offer a tribute, even if it lasted only a few moments.

Overnight, volunteers distributed blankets and cups of tea to people in line as temperatures fell to 6 degrees Celsius (43 degrees Fahrenheit). Despite the weather, mourners described the warmth of a shared experience.

“It was cold overnight, but we had wonderful companions, met new friends. The camaraderie was wonderful,″ Chris Harman of London said. “It was worth it. I would do it again and again and again. I would walk to the end of the earth for my queen.”

People had many reasons for coming, from affection for the queen to a desire to be part of a historic moment. Simon Hopkins, who traveled from his home in central England, likened it to “a pilgrimage.”

“(It) is a bit strange, because that kind of goes against my grain,” he said. “I’ve been kind of drawn into it.”

Saturday’s vigil followed one on Friday in which the queen’s four children — Charles, Anne, Andrew and Edward — stood vigil at the coffin.

Edward said the royal family was “overwhelmed by the tide of emotion that has engulfed us and the sheer number of people who have gone out of their way to express their own love, admiration and respect (for) our dear mama.”

On Saturday, the new king was holding audiences with incoming prime ministers, governor generals of the realms and military leaders.

The Metropolitan Police arrested a man Friday night during the viewing for a suspected public order offense. Parliamentary authorities said someone got out of the queue and tried to approach the coffin.

Tracey Holland told Sky News that her 7-year-old niece Darcy Holland was pushed out of the way by a man who tried to “run up to the coffin, lift up the standard and try to do I don’t know what.” She said police detained the man in “two seconds.”

The lying-in-state continues until early Monday morning, when the queen’s coffin will be borne to nearby Westminster Abbey for a state funeral, the finale of 10 days of national mourning for Britain’s longest-reigning monarch. Elizabeth, 96, died at her Balmoral Estate in Scotland on Sept. 8 after 70 years on the throne.

After the service Monday at the abbey, the late queen’s coffin will be transported through the historic heart of London on a horse-drawn gun carriage. It will then be taken in a hearse to Windsor, where the queen will be interred alongside her late husband, Prince Philip, who died last year.

Hundreds of troops from the British army, air force and navy held an early-morning rehearsal Saturday for the final procession. As troops lined the picturesque path leading to Windsor Castle, the thumping of drums echoed in the air as marching bands walked ahead of a hearse.

London police say the funeral will be the largest single policing event the force has ever handled, surpassing even the 2012 Summer Olympics and the Platinum Jubilee in June celebrating the queen’s 70-year reign.