The Beijing Olympic flame was welcomed by cheering children amid tight security in China on Monday, a symbolic start to the Games that has been overshadowed by unrest in Tibet and concerns over human rights.

What was envisioned as the start of a torch relay around the world to illustrate unity ahead of the August 8 opening of the Games 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.

On Monday, the flame was escorted off a plane emblazoned with "Journey of Harmony" and passed to officials in a tightly choreographed display outside a gleaming new airport terminal where groups of children waved Chinese and Olympic flags.

The flame, encased in a lantern, was to be officially welcomed at a ceremony at Tiananmen Square, the focus of democracy protests that were crushed in 1989, where police and plainclothes security men lined streets cordoned off with yellow tape.

"It's a special day," said Zhang Jing, 25, who could not get to the square because of the security. "It gives our country some nobility and gives us something to be proud of."

At the ceremony, to be attended by President Hu Jintao, a second flame will be lit and taken to Tibet where an attempt will be made to take it to the top of Mount Everest in early May.

The square was decked out in a red carpet, with rows of ethnic dancers, including Tibetans, and brightly dressed students, workers and other supporters waving pom-poms and singing the Olympic motto "One World One Dream" as they awaited the flame's arrival.

The scenes mark a contrast from the mood overseas, where exiled Tibetans and human rights activists have targeted the Olympics since China poured security forces into Tibet and parts of western China to suppress anti-government protests.

In Athens, protesters holding Tibet flags and shouting "Free Tibet" and "China out of Tibet" failed to break through a police cordon to block the flame's passage.

China blames the Dalai Lama for days of protest in Lhasa, that burst into a citywide riot on March 14, and other unrest throughout its ethnic Tibetan regions.

It says he is seeking independence for the region Communist troops entered in 1950 and wants to disrupt the Beijing Olympics, a charge the Dalai Lama, who has lived in exile in India since a failed 1959 uprising against Chinese rule, denies.

Foreign Ministry spokesman Qin Gang last Thursday made clear China's opposition to any protests surrounding the torch relay.

"We condemn these shameful acts which violate the spirit of the Olympics and the common aspirations of people worldwide," he told a news conference.

"We believe the torch relay, with the support of people worldwide, will be smoothly held."

The international leg of the 130-day relay starts when the flame heads for Kazakhstan on Tuesday. The flame returns to Beijing after travelling around all of China's provinces and regions on August 6, two days before it is used to light the cauldron at the Olympic opening ceremony.