President Hu Jintao lit a cauldron with the Olympic torch in Beijing's Tian'anmen Square Monday morning, launching the official start of the worldwide torch relay of the 2008 Beijing Olympic Games.

Hu then passed the torch to hurdler Liu Xiang, the men's 110m Olympic and world champion, who ran across the Golden Water Bridge in front of Tian'anmen Rostrum.

Thousands of spectators gathered at the world's largest square to welcome the arrival of the flame with a grand celebration which included the performance of Peking opera, folk acrobatics and ethnic dances.

The flame was ignited in ancient Olympia on March 24 and after a torch relay in Greece, was handed over to the hosts in Athens on Sunday. It was carried back on a specially-chartered Air China plane to the capital at around 9 am yesterday.

Vice-President Xi Jinping expressed his best wishes to the Olympic torch relay and the Olympic Games at the welcome ceremony.

"The Chinese government and people warmly welcome athletes and friends from all countries and regions to Beijing for the grand Olympic event

"Starting from here, the torch relay of the Beijing Olympic Games will pass across land and sea, connect the hearts and minds of people of five continents, and spread the message of 'one world, one dream' to every corner of the world," Xi said.

The Beijing Olympic 2008 torch relay is the longest in Olympic history, passing 134 cities in 130 days with 21,880 torchbearers covering 137,000 km.

The relay will take the flame to five continents, including 21 cities outside the Chinese mainland, 113 cities of all 31 provinces, autonomous regions and municipalities on the Chinese mainland and Mount Qomolangma (Everest), the highest point on Earth.

Xi said the torch relay will further imbue the Olympic spirit among 1.3 billion Chinese people.

"It will release the passion of all the Chinese people for the Olympic Games, create an enthusiastic and vibrant atmosphere in the whole society and showcase the commitment of Chinese people to welcome, participate and contribute their share to the Olympic Games," he said.

International Olympic Committee President Jacques Rogge said in a message read out by IOC Coordination Commission Chairman Hein Verbruggen at the ceremony: "It is the torch's ability to touch us that allows it to reach out to the world, beyond the host city, to bring the Olympic values closer to society and call the people of the world to the Games."

Rogge said the Olympic torch is one of the most well-known and potent symbols of the Olympic movement, heralding not just the arrival of the Games but also spreading a message of peace, or "Ekecheiria" as the Greeks call it, to the world.

"I am certain that the Games will not only be a moment of sporting excellence, but also an opportunity for the people of China and the world to learn, discover and respect each other."

Many Beijing Olympic torchbearers expressed their good wishes for the journey.

Marcos Antonio Terres, a 39-year-old Filipino, told China Daily that he wished the global torch relay is "as harmonious as planned".

"The torch relay is supposed to be a symbol of peace, goodwill and friendship; and people should be inspired by those values," he said. "I feel upset that some people are trying to disrupt the torch relay and it should not be tinted with politics."

Chinese torchbearer Tu Yueming, a Beijing resident who keeps a close eye on the relay news, said: "I am praying it will be a success and I hope my friends can cheer for me on the streets," he said.

The international leg of the "Journey of Harmony" begins today at the Kazakh city of Almaty.

The flame finally arrives at the National Stadium in Beijing on Aug 8 for the opening ceremony.