Crowds of Chinese students waving red flags scuffled with pro-Tibet protesters and Japanese nationalists in yesterday's leg of the Olympic torch relay.
The global torch relay ahead of the Beijing Games in August has prompted protests against China's human rights record as well as patriotic rallies by Chinese who criticise the West for vilifying Beijing.
As rain fell in Nagano, chants of 'Go China' mixed with 'Free Tibet' from the rival groups, who clashed at times despite tight security in the central city, host to the 1998 Winter Olympics.
Four Chinese supporters were injured and five men were arrested, fire officials and police said, including one man who was wrestled to the ground after running into the relay path holding a Tibetan flag and shouting 'Free Tibet'.
More than 3,000 police were mobilised for the relay, which comes a day after China's Xinhua news agency said Beijing would hold talks with representatives of the Dalai Lama, the exiled Buddhist leader of Tibet, whom it blames for recent unrest.
Other arms of China's state media, however, kept up their condemnation on Saturday of the Dalai Lama, who fled into exile in India in 1959 after a failed uprising against Communist rule.
Japan, whose ties with Beijing are often tense due to Chinese bitter memories of the wartime past, was keen to avoid the chaotic scenes that marred some of the relay venues elsewhere ahead of next month's high-profile visit by President Hu Jintao.
"I ran hoping for the Beijing Olympics to be successful and peaceful," said Japanese Olympic gold medallist marathon runner Mizuki Noguchi, after lighting the flame on the podium at the end of the relay.
Commenting on the turmoil that has bedevilled the global relay, International Olympics Committee (IOC) President Jacques Rogge urged the West to stop hectoring China over human rights.
"You don't obtain anything in China with a loud voice," Rogge told yesterday's Financial Times. "That is the big mistake of people in the West wanting to add their views".
Analysts and activists expressed caution about prospects for any easing of tensions in Tibet through dialogue between Beijing and the Dalai Lama's representatives.
"It's too early to tell if the meeting will produce results or is just for PR purposes in advance of the Olympics," Mary Beth Markey, a vice-president at the International Campaign for Tibet, said in a statement.
In Nagano, 100 Japanese police officers shielded the torch-bearers in two rows on each side, accompanied by two Chinese 'flame attendants' in blue-and-white track suits, while pro-China supporters waved red national flags along the route.
Scuffling broke out between pro-China and pro-Tibet groups, among whom were many Japanese right-wing activists, near Nagano's main train station. Police separated the rival groups. TV footage showed one injured man, with blood on his face.
A small group of Amnesty International members protested in front of Nagano station, wearing blindfolds and chanting 'Human Rights for China'. They were approached by a crowd of Chinese supporters chanting back 'Liars, liars'.
Around 80 torch bearers took part in the 18.7 km relay through the city, including Olympic stadiums.
When the relay drew to an end, a crowd of Chinese supporters, singing and chanting 'One China' faced off with pro-Tibet protesters chanting 'Free Tibet' from different sections of the park where the closing ceremony was held, kept well apart by a wall of police.
"We want to protect the Olympics," said 35-year-old Chinese student Cheng Hon. "Violence is wrong."
The flame, which travels next to Seoul, is meant to transmit a message of peace and friendship, but its journey has been largely turned into a political event and the torch has been granted the sort of security usually reserved for state leaders.