Chants and drum beats echoed off the faceless, stone buildings of Whitehall on Saturday as several thousand marched past the seat of Britain's democratic government to highlight Burma's plight.
Monks led the way past Parliament
Led by about a dozen monks, sober-faced and swathed in their saffron robes, protesters of all ages yelled: "What do we want? Democracy. When do we want it? Now".
Big Ben tolled midday as they crossed Westminster Bridge and curious tourists stopped with mobile phones to capture the spectacle of banners and red headbands.
"No more bloodshed. Free Aung San Suu Kyi," read the Amnesty International banners. Others proclaimed "Security Council Action Now".
The London event was one of many planned for around the world, including rallies in Austria, Australia, Belgium, Canada, France, India, the Irish Republic, New Zealand, Norway, South Korea, Spain, Thailand and the US.
Howard Nguyen, 57, originally from Vietnam, marching with his family, said: "We are here supporting democracy in Burma. They have a very much suppressive government and we want to add our voice to protect the people there.
"People round the world must put pressure on the Burmese government. If we do nothing then the Burmese government will have a free hand."
A row of police walked in front of the march, with others lining the route from Pimlico to Trafalgar Square - more to keep the traffic lanes clear than to keep the demonstrators in line.
One policewoman even helped a young boy tie his red ribbon, the colour of the Burmese flag, round his head.
Photographers were scattered everywhere, using the tricks of the trade to get the perfect shot - lying on the road, clambering up convenient walls, perched on statues.
It was in contrast to the images of the Burmese crackdown which had to be taken secretively and smuggled out of the country as media was prevented from freely reporting the events of the past few days.
The junta cracked down on pro-democracy protests, with at least 10 people killed, but UN special envoy Ibrahim Gambari said he feared the real death toll could be much higher.
He said there was great concern over reports of night-time raids, arbitrary arrests, mass relocations and beatings.
For Mark, carrying his four-year-old daughter Molly on his shoulders, the images had spurred him to join the protest. "I saw some horrific images on TV and we just wanted to show our support," he said as Molly waved a home-made banner saying "Down with the junta".
Monks tied red ribbons on the Downing St gates
The march paused briefly outside Downing St to allow the monks to tie red cloth around the bars of the gates to the prime minister's residence. The crowd clapped as the monks continued on their way.
Standing in Trafalgar Square, Jo Lee Morrison cries as she explains why she has marched.
"This is really emotional for me. It has been too long since anyone has cared for the Burmese people. Now that people are looking we have to do something, and show solidarity with them."
Her interest in Burma was sparked five years ago when she lived on the Thai border with Burma, teaching English to Burmese refugees.
"I hope this march will show activists in Burma that we care and will keep putting pressure on western governments and China and India.
"Bringing democracy to Burma won't happen in an afternoon - there needs to be big geopolitical changes."
Wiping away tears, she says: "It's like Aung San Suu Kyi said: 'Please use your liberty to promote ours'."
Her friend, Sylvia Rowley, hopes the visible presence in London will at least maintain the issue high on news bulletins. "At the very least it will make this happen," pointing to her placard which states "Don't forget Burma".