A stream of mourners laid flowers and tributes outside Buckingham Palace on Friday, as it became the focal point of a country grieving the death of Queen Elizabeth II.

Stony-faced soldiers in red coats and bearskin hats stood guard by the palace, the late queen's London headquarters during her 70-year reign.

Mourners stood silently and watched, while some placed bouquets in the black railings of the landmark residence.

"We just wanted to pay tribute to the queen," said Natalie Vehring, a violinist who has performed at concerts attended by the queen.

She was at the palace with her husband and two sons in school uniform, while on a video call with her mother in Australia.

"My mum says she remembers the king dying," added the 46-year-old, referring to the queen's father, George VI, who died in 1952.

"I grew up in Australia, the monarchy was a very huge part of our childhood, we sang the national anthem every day at school.

"It's amazing how she was working a day before her passing," she added.

People left candles in glass jars, rain-sodden Union Jack flags, newspapers bearing the late queen's image and personal notes.

"Thank you. You served our country to the end. Faithful in God," said one message.

"Thank you for your service Ma'am. You were a guiding light in dark times, the foundation of a nation, our strength and stay. Rest in peace," read another.

One note, signed by "the coffee ladies", said: "Beautiful Queen. Thank you, thank you for your constancy, your loyalty and long reign".

- 'Devastated' -
 

Joan Russell, 55, a project manager from east London, had tears running down her cheeks as she looked at the flowers.

"I came to say a prayer," she told AFP.

"Charles has had such a great example to follow. I believe he will do his very utmost to continue the legacy of his parents."

There were similar scenes in Windsor, west of London, as well-wishers, many crying, left hundreds of bouquets and lit candles outside the gates of the late queen's beloved castle.

One of those in tears was Marina Flynn, 79, whose husband used to work with the queen's husband, the Duke of Edinburgh.

"She was wonderful, she's done nothing wrong. I met her a couple of times with the Duke and they were always really nice. I just feel devastated," said Flynn, dressed in black.

Others expressed concern about the new King Charles III.

"Oh I'm worried about what he would do," said Estrella Linch, 78.

"He is not a decisive man, he doesn't know how to take big decisions," she added.

In Scotland, the former queen's residence at Holyroodhouse in Edinburgh, which will house Elizabeth's coffin before it travels to London, also became a focus of tributes.

Locals and curious tourists came to contemplate silently and lay flowers, as preparations began to welcome the queen's coffin.

Gardeners were hard at work getting the lawns in order, with the smell of cut grass and rain wafting across the Scottish capital.

"All this pomp and glory is going to be a nice thing and a very sad thing," said Rebecca Evans, 44, who works for a climate change think-tank.

"It's going be an interesting few days."