Gun salutes echoed around the United Kingdom on Saturday as the military paid solemn tribute to Queen Elizabeth II's husband Prince Philip after his death at the age of 99.

The coordinated 41-round volleys to the former Royal Navy commander were fired at a rate of one per minute from 12:00 (11:00 GMT) in London, Edinburgh, Cardiff and Belfast, as well as at naval bases, from warships at sea, and in the British territory Gibraltar.

Similar salutes — the most according to military protocol — were also held in Canberra and Wellington, as the queen is head of state in Australia and New Zealand.

At the Tower of London, a crowd of more than 100 onlookers kept a respectful silence as they watched the Honourable Artillery Company fire shots on the banks of the River Thames.

One onlooker, Heather Utteridge, said she had come to show her respects "for a superhuman".

"It’s a great loss to not just the queen, but actually to the country. He represented stability for all of our lives,” the 65-year-old told AFP.

Alexander Beaten, 30, said the royal couple, who had been married for 73 years, had been an integral part of British identity and culture.

"We can disagree with the government, we can disagree with so many things that the country may or may not do, but the Queen Elizabeth and Prince Philip are just such a constant,” he said.

Sporting events, including Premier League football matches and at English county championship cricket, held moments of silence as part of worldwide tributes to mark the death of the Duke of Edinburgh, during a period of national mourning.

The death of the duke, the longest serving royal consort in British history, on Friday is a profound loss for the 94-year-old monarch, who once described her loyal husband as her "strength and stay” throughout her long reign.

Flags half mast 

Flags are flying at half-mast on government buildings and will do so until the morning after his funeral, the date of which has yet to be announced.

The well-rehearsed protocol for the duke’s death — codenamed "Forth Bridge” — includes the recall of parliament on Monday.

British television stations cleared their schedules for special broadcasts looking back on his life, although the BBC said it had received complaints about the blanket coverage.

Westminster Abbey, where the couple married in 1947, tolled its tenor bell 99 times on Friday, once for each year of the prince’s life.

Political campaigning for May local elections stopped, and loyalist leaders in Northern Ireland, who have been rioting for days amid heightening political tensions in the British province, urged a pause in violence on Friday.

The call — "as a mark of respect to the queen” — was largely heeded.

Marches that had been planned by members of the pro-UK unionist community in Belfast were cancelled on Saturday.

But despite the calls for calm, some lower-level disorder continued overnight.

‘Deep sorrow’ 

Philip — who would have celebrated his 100th birthday in June — had been ill for some time, and spent more than a month in hospital from February 16 being treated for a pre-existing heart condition and an infection.

Despite looking frail on his release from hospital on March 16, hopes were raised for his recovery.

But the queen announced Philip’s passing "with deep sorrow” after he died peacefully on Friday morning at Windsor Castle, west of London.

Philip’s eldest son and the queen’s heir, Prince Charles, reminisced about his father in pre-recorded comments aired in a special BBC programme on Friday.

"Well, you know he didn’t suffer fools. So if you said anything that was in any way ambiguous — he’d say ‘make up your mind!’” Charles said.

The queen and the duke’s two youngest children — Prince Andrew and Prince Edward — both visited Windsor Castle on Saturday morning. Prince Charles saw his mother there on Friday.

‘Farewell, my beloved’ 

The duke’s death dominated Britain’s newspapers on Saturday. "We’re all weeping with you Ma’am,” The Sun tabloid said on its front page.

The Daily Mail splashed a photo of the queen looking at her husband along with the headline "Farewell, my beloved” on the front page of its 144-page souvenir edition.

Tributes came in from home and abroad, with Prime Minister Boris Johnson giving "thanks, as a nation and a kingdom, for the extraordinary life and work of Prince Philip”.

Political and faith leaders in Britain, and from the United States, Europe and Commonwealth countries including Australia, Canada, India, New Zealand and Pakistan also paid their respects.

Global royalty also paid their respects, while Pope Francis praised the prince’s "devotion” to his family and marriage, and sent his "heartfelt condolences” to the queen.

Harry’s likely return 

Philip is expected to be buried at St George’s Chapel in Windsor Castle, according to the royal College of Arms, at a date to be determined.

His grandson, Prince Harry, is likely to make his first return to Britain since his shock move to the United States last year, British media reported.

Philip retired from public duties in 2017 at the age of 96, declaring "I’ve done my bit”.

The couple had been living largely in isolation at Windsor because their age put them at heightened risk from COVID-19.

He was last seen at a staged appearance at a military ceremony at Windsor in July, days after attending the wedding ceremony of his granddaughter Princess Beatrice.

Much of the planning for the funeral has had to be adapted to avoid the gathering of large crowds, because of strict coronavirus restrictions.

On Saturday members of the British public continued to pay their respects outside Buckingham Palace and Windsor, despite royal family requests for people not to gather at royal residences because of the restrictions.

Hundreds of flowers that had been layed outside the Queen’s official residence in central London on Friday have been moved to Windsor to apparently to discourage further gathering.

An online book of condolences on the royal family’s official website has been put in place rather than conventional public tributes, and no lying in state.