SEOUL, South Korea — Chinese students clashed with anti-Beijing demonstrators at the Olympic torch relay today in Seoul, throwing rocks and punches at the latest stop on the flame's troubled round-the-world journey.

A North Korean defector tried to set himself on fire to halt the relay, where thousands of police guarded the flame from protesters blasting China's treatment of North Korean refugees.

But the small groups of anti-China demonstrators were far outnumbered by seas of red-clad Chinese supporters who waved red national flags as they took to the streets of the South Korean capital to defend the torch.

Police deployed 8,000 officers, some running beside the flame while others rode horses and bicycles with the relay through the city, which hosted the 1988 Summer Olympics.

China's crackdown on violent protests against Chinese rule in Tibet has triggered attempts to disrupt the torch run celebrating the August games at other stops of the torch relay.

In South Korea, many critics focused on Beijing's treatment of defectors who try to escape their lives of hardship in North Korea.

Thousands of North Koreans have fled across the loosely controlled Chinese border and many remain in hiding in China. If caught, they are deported by Chinese authorities and face likely imprisonment in life-threatening conditions back in the North.

The man who tried to immolate himself, 45-year-old Son Jong Hoon, had led an unsuccessful public campaign to save his brother from execution in the North, where he was accused of spying after the two met secretly in China. About an hour into the relay, Son poured gasoline on himself in the middle of a street, but police quickly surrounded him and carried him away before he could set himself on fire.

Two other demonstrators tried to storm the torch but failed to hinder its 15-mile trip from Olympic Park — built in honor of the 1988 Summer Games — to City Hall.

Police said five people, including a Chinese student, were arrested.

Scuffles broke out near the relay start between a group of 500 Chinese supporters and about 50 demonstrators criticizing Beijing who carried a banner that read: "Free North Korean refugees in China." The students threw stones and water bottles as some 2,500 police tried to keep the two sides apart.

One Chinese student swatted at the demonstrators with a flagpole. Another student was arrested for allegedly throwing rocks, said an official at a police station near Olympic Park. The official asked not to be named because the investigation was under way.

"The Olympics are not a political issue," said Sun Cheng, 22, a Chinese student studying the Korean language in Seoul. "I can't understand why the Korean activist groups are protesting human rights or other diplomatic issues."

Thousands of Chinese paced the torch on the 4½-hour-long relay, some chanting, "Go China, go Olympics!"

Before the relay, two South Koreans who had been chosen to run said they would boycott it to protest China's actions in Tibet.

The torch arrived in Seoul from Japan, where Chinese supporters also outnumbered protesters who failed to disrupt the run.

After Seoul, the torch is scheduled to make its first-ever trip to North Korea for a relay Monday.

Officials from North Korea's Olympic Committee, the Pyongyang city vice mayor, and the Chinese ambassador to Pyongyang were at the airport early Sunday to greet the torch's arrival, APTN North Korea reported. A 12.4-mile relay will take place in the streets of Pyongyang on Monday.

Associated Press writers Kwang-tae Kim and Jae-hyun Jeong contributed to this report.