Olympic torch bearers dashed past sporadic protests Saturday as heavy security marked the Japanese leg of the world relay _ streets lined by thousands of riot police and monitored by helicopters overhead.

Police guards in track suits surrounded the torch bearers and another 100 uniformed riot police trotted alongside six patrol cars and two motorcycles. They were backed up by thousands of other police.
Japanese officials said the high security was unavoidable, but it dissipated any festive mood in Nagano, which hosted the 1998 Winter Games.
Minor scuffling and protests broke out during the event.
Three men were arrested separately during the relay, each trying to charge the torch, and a fourth man was apprehended later after throwing eggs at a torch runner. A fifth hurled tomatoes at the flame. All were pounced on by police, police officials Akiko Fuseya and Chihiro Usui said.
National broadcaster NHK reported a smoke-emitting tube was thrown at the relay, but without effect. Marchers yelling "Free Tibet" crowded the streets near the route. And four people were slightly injured in different scuffles, fire officials said.
The starting point _ a last-minute substitution after a Buddhist temple pulled out _ was closed to the public, as were all rest stops along the way.
The relay leg ended at a Nagano park much as it had traversed the mountain resort _ amid a sea of both Chinese supporters and pro-Tibet demonstrators.
"I'm so glad that I could safely light up the cauldron," said marathon gold medalist Mizuki Noguchi, the final torch runner. "I ran as I wished for the success of the Beijing Olympics and peace."
The relay, making its 16th international stop, has been disrupted by protests or conducted under extremely heavy security at many sites since it left Greece.
The protests are largely in response to China's crackdown last month on protests in Tibet, which it has governed since the 1950s, and to demonstrate against China's human rights record.
The international route ends next week, with stops in South Korea on Sunday, North Korea on Monday and Vietnam on Tuesday. The flame arrives on Chinese soil on Wednesday in Hong Kong, for a long journey around the country before the Aug. 8 start of the games.
Japan took severe measures to ensure its 11.6-mile relay went smoothly.
But groups including Amnesty International and Reporters Without Borders planned to protest peacefully throughout the day. About 2,000 Chinese exchange students, meanwhile, swarmed Nagano to show their support.
"I hope there won't be any more problems. The Olympics are supposed to be about international unity," said Gao Rui, who came with his family waving Chinese flags.
Several hundred more, divided into pro-China and pro-Tibet factions, rallied in front of the train station. Some marchers yelled "Free Tibet" and waved Tibetan flags, crowding the streets along the route.
"I came from Tokyo to show my support for Tibet," said Toru Watanabe. "I'm glad it was peaceful, but it was impossible to see the torch."
Coinciding with the start of the relay, which began under a light rain, a prayer vigil was held at the largest Buddhist temple in Nagano, Zenkoji.
The 1,400-year-old temple, which was the showcase of the 1998 Olympics, last week declined to host the start of the relay, citing security concerns and sympathy among monks and worshippers for their Buddhist brethren in Tibet