Hu's visit is the first to Japan by a Chinese president in a decade.
Police guards in tracksuits surrounded the first runner, the manager of Japan's national baseball team, and another 100 uniformed riot police ran alongside six patrol cars and two police lead motorcycles.
The starting point, which was in a car park after a Buddhist temple withdrew in a protest at China's crackdown in Tibet, was closed to the public, as were all the rest stops.Rubbish thrown
But pro-Tibet demonstrators, along with other activists including Japanese nationalist groups, managed to throw rubbish and eggs at the torchbearers as they passed.
Some protesters shouted "Free Tibet" and waved Tibetan flags, as the torch passed along the route.
|Large crowds of Chinese students travelled|
to Nagano for the relay [Reuters]
Angry Chinese supporters surrounded demonstrators and during one brawl, the Chinese charged with flagpoles and anti-Beijing demonstrators kicked them until police broke up the two sides, witnesses said.
Witnesses said one young man, who appeared to be Chinese, was seen on the ground with cuts on his forehead as supporters wrapped him in a red Chinese flag.
"At first I didn't think I would come here as I didn't have the time or money," Xin Xin, a 24-year-old student wearing a Chinese flag, said.
"But many things happened this past week. We had to come here to support the Olympic games in China," he said.
At the end of the relay, police pushed back anti-China protesters who had tried to disrupt the procession. The demonstrators shouted at Chinese supporters who were separated on the other side of the street.
"China kills Tibetans, who are a very peaceful people, so I hate the Chinese government. I want Tibet to become independent," Hisakazu Hattori, a 21-year-old Japanese student, said.
The protests came after Beijing agreed to meet a representative of the Dalai Lama. However, it also repeated preconditions for negotiations, including that Tibet's spiritual leader recognise Tibet as part of China.
Jacque Rogge, the International Olympics Committee president, has urged the West to lay off China, saying that Beijing should be given time on human rights.
"You don't obtain anything in China with a loud voice," Rogge told the London-based Financial Times newspaper.
"To keep face [in Asia] is of paramount importance. All the Chinese specialists will tell you that only one thing works - respectful, quiet but firm discussion."
"Otherwise the Chinese will close themselves. That is what is happening today. There is a lot of protest, a lot of very strong verbal power, and the Chinese, they close themselves."
The relay will move to the South Korean capital Seoul on Sunday.