Thousands of people across Asia and Europe took part in human rights protests Friday as China launched the Beijing Olympics with a dazzling, three-hour opening ceremony.

Demonstrators took to the streets of London, Brussels, Berlin, Amsterdam, Kathmandu, Bangkok, Hong Kong and New Delhi among other cities over concerns ranging from China's rule of Tibet to its support for Myanmar's military junta.

China has painted the Games as a celebration of three decades of economic reforms and hopes it will showcase a rapidly modernising country.

But activists across the world are using them to pressure Beijing over its rule of Tibet and the heavily Muslim Xinjiang province, the arrests of dissidents, censorship and concerns about Chinese foreign policy.

Three foreign protestors managed to breach tight security near the Bird's Nest Olympic stadium in Beijing to stage a brief, 40-second protest and pull out Tibetan flags an hour before the opening ceremony burst into life.

Americans Jonathan Stribling-Uss, 27, and Kalaya'an Mendoza, 29, as well as Cesar Pablo Maxit, 32, an Argentine-American, were immediately and forcibly detained by Chinese security, Students For A Free Tibet said in a statement.

Police did not immediately comment.

Earlier in the day, Reporters Without Borders hacked into Chinese airwaves to broadcast a 20-minute programme in Chinese, English and French at 8:08 am (0008 GMT) -- exactly 12 hours before the opening ceremony in Beijing.

The French-based media rights group said it was the first of its kind in China since the communists seized power in 1949.

At least 1,400 Tibetans including scores of monks and nuns were arrested by Nepalese police during a protest against Beijing's rule of the Himalayan region.

Demonstrators shouted "Shame shame, Hu Jintao," referring to the Chinese president, and "Tibet belongs to Tibetans".

"We want to give the millions of people who will watch the opening as well as the hundreds of athletes taking part the message that there are no human rights in Tibet," Tibetan student Tashi Tsering, 20, told AFP in Kathmandu.

In Ankara, a protestor tried to set himself alight outside China's embassy as some 300 Chinese Muslim refugees rallied to denounce human rights violations in their home region of Xinjiang.

The man in his 30s burned his face and hands before police intervened and extinguished the flames.

In London, around 300 protestors gathered opposite the Chinese embassy, many of them Tibetan exiles wearing red headbands bearing one word: "Killed."

And in Brussels, around 200 Tibetan protesters, some chained together or wearing 'bloody' bandages, protested near the headquarters of European Union institutions.

"The blood continues to flow in Tibet," said organiser Nyima Chushisu, as she put bandages on a fellow demonstrator.

Dozens of Reporters Without Borders campaigners gathered outside the Chinese embassy in Berlin brandishing placards saying China was a "prison" for journalists.

More than 60 protesters rallied outside Myanmar's embassy in the Thai capital Bangkok to demand that China end its support for the ruling junta in Yangon.

US President George W. Bush, in Beijing for the opening ceremony, hailed the growing relationship between the United States and China, even as he urged Beijing to accept greater freedom of expression and religion.

"I strongly believe societies that allow the free expression of ideas tend to be the most prosperous and the most peaceful," Bush said. "I will continue to be candid about our mutual global responsibilities."

French President Nicolas Sarkozy told French television he discussed human rights with Chinese leaders in Beijing and handed them lists of jailed dissidents.

In Paris, hundreds of human rights activists, Tibet supporters and Reporters Without Borders activists rallied outside the Chinese embassy. Some had a banner showing the five Olympic rings as handcuffs and carried coffins.

About 1,000 people demonstrated in the central Italian town of Assisi, calling for greater rights in China and Tibet, according to the Italian Radical Party which organised the event.

In Hong Kong, a Briton, Matt Pearce, was arrested after climbing on to a bridge and unfurling two protest banners that read: "The people of China want freedom from oppression" and "We want human rights and democracy."