Smiling Tibetan students dancing in national dress, acrobats in lime green leotards and hundreds of armed police and plainclothes security officers filled Tiananmen Square yesterday for the arrival of the Olympic flame.

Marking the symbolic start to the Beijing Games, President Hu Jintao took the flame and lit a cauldron on a red-carpeted rostrum under the gaze of Chairman Mao Zedong whose giant portrait hangs at the north end of the square.

He then handed the torch to Olympic champion hurdler Liu Xiang who officially opened the 130-day relay before the cheering crowd.

Roads were closed off, two subway stations closed and no members of the public were allowed onto the square in a huge security operation intended to ensure the ceremony went off without a hitch.

Demonstrations by pro-Tibet activists, protesting over the security clampdown that has followed recent deadly anti-Chinese riots in the Himalayan regions, have dogged the first week of the torch relay in Greece.

One group of Tibetans was prominent on the square – dancers from the Minorities University in Beijing who joined a bevy of ethnic minority performers.

In China, the arrival of the flame triggered a wave of proud delight. One middle-aged woman from a Beijing district dance group, notified only a day earlier that her team had won a place on Tiananmen Square for the ceremony, said: “We are so happy. This is a great moment for China. This is a once in a lifetime opportunity for us.”

The presence of Mr Hu highlighted the significance that China attaches to the Games, starting on August 8. As the president declared the start of a torch relay that will pass through 21 countries and involve more people than ever before, doves were released, red, pink, green and blue balloons fluttered into the sky and drums pounded.

Xi Jinping, the President’s heir-apparent and the man overseeing Olympic preparations, said: “The century-old dream of the Chinese people to host the Olympic Games has been turned into a reality.”

But what was envisioned as a torch relay around the world that would illustrate unity has instead become a lightning rod for protests.

Activists unfurled banners condemning China’s rights record at last week's flame-lighting ceremony in Greece and on Sunday a small group of protesters tried to block the flame's handover to Beijing officials.

The flame, encased in a lantern, was escorted off a specially equipped plane emblazoned with the words: "Journey of Harmony" and brought to Tiananmen Square, the focus of democracy protests that were crushed in 1989. In the square, the flame was split in two for the first time in its history.

One flame will be taken to Tibet where climbers, training for years, plan to carry it to the peak of Mount Everest – the world’s highest mountain. The second flame will journey around the world before returning to China in early May for a journey encompassing every province. Security is certain to be tightest in the Tibetan capital, Lhasa.

Times Recommends

• No apology for Germany’s own Nazi victims
• Intricate web of fear and hope tying down deal
• Victims remembered a year after Mumbai attacks