President Hu Jintao on Tuesday started the first visit by a Chinese leader to Japan in 10 years as the Asian powers eased decades of tension, but hundreds took to the streets to protest over Tibet.

Just three years after relations hit rock bottom, Hu has said his trip would herald a "warm spring" with Japan, which is a top commercial partner despite the lingering resentments of many Chinese over Tokyo's past aggression.

Japanese Foreign Minister Masahiko Komura personally went to Tokyo's Haneda airport to greet Hu, who smiled and waved as more than 200 Chinese people chanted "Welcome! Welcome!" and offered him bouquets of flowers.

"Japan and China are both important countries in Asia and the world," Hu said in a statement issued on arrival. "Through this visit, I hope to increase mutual trust, reinforce our friendship and deepen our cooperation.

But while Japan and China have been working for years to repair ties, the visit threatens to be overshadowed by unrest in Tibet.

It is Hu's first overseas visit since major protests broke out in Tibet in March against China's rule. Beijing's subsequent crackdown has triggered a worldwide uproar, casting a shadow over the upcoming Olympics.

Thousands of police were on hand to ensure security, keeping Hu out of sight of Japanese nationalists who drove vans across Tokyo blaring anti-Chinese slogans.

Elsewhere in Tokyo, nearly 1,000 demonstrators marched with Tibetan flags and signs reading, "Don't kill our friends."

Opposition lawmaker Yukio Edano told the rally that Prime Minister Yasuo Fukuda should raise the Tibet issue forcefully with Hu.

"If Prime Minister Fukuda's meeting with President Hu Jintao is a mere formality, that means that we are accomplices in China's crimes in Tibet," Edano said.

The five-day visit will be Hu's longest trip to a single foreign country since he took power in 2003 and only the second ever by a Chinese head of state to Japan.

But the trip was expected to be largely about symbolism, with Hu slated to show his hand at ping-pong and tour historic temples. The two countries failed to resolve a heated territorial dispute over gas fields in time for the summit.

In a sharp contrast to previous summits between Japan and China, both sides have signalled that emotionally charged rows over history will be left on the back burner.

"I sincerely hope the people of the two countries can maintain friendship generation after generation and create a brighter future for the Sino-Japan friendship," Hu said in a written message to a Japanese-language magazine.

Addressing a populist concern, Hu has promised to consider finding a replacement for the Tokyo zoo's beloved panda Ling Ling, who died last week.

The only other visit by a Chinese president to Tokyo, by Jiang Zemin in 1998, was overshadowed by feuding on whether Japan had adequately apologised for invading China in the 1930s.

Jiang's visit -- particularly his public berating of Japan in front of the emperor -- left a lasting bitter taste in the mouths of some Japanese and foreshadowed the rise of politicians who have taken a harder line with Beijing.

A poll published this week by the Mainichi Shimbun showed that most Japanese people believed the country should be tougher with China.

Junichiro Koizumi, who served as prime minister from 2001 to 2006, infuriated Beijing by going each year to the Yasukuni shrine, which venerates 2.5 million Japanese war dead including top World War II-era leaders.

Fukuda, the current prime minister, is a longtime advocate of reconciliation with China. His father, Takeo Fukuda, as premier signed the landmark 1978 peace and reconciliation treaty with China.

But unlike Koizumi, Fukuda is deeply unpopular, with his government's approval rating plunging as low as 18 percent in recent polls due to domestic issues.

PHOTO CAPTION:

Chinese President Hu Jintao waves to wellwishers upon his arrival in Tokyo.

AFP