Protestors managed to disrupt the Olympic torch run in Beijing Wednesday, despite China's massive security efforts leading up to the 2008 Summer Games.

Early in the morning, protestors from Students for a Free Tibet unfurled massive banners from huge towers at the Beijing Olympic park.

The banners carried the slogans "Tibet will be free" and "One World, One Dream, Free Tibet."

Four protestors, all foreigners, managed to scale the towers to hang the banners but they were later led away by police. Olympic officials said they were not arrested.

Organizers condemned the demonstration, which was the first at the Beijing Olympics. The demonstration was the first at the Beijing Olympics and was condemned by organizers.

"We express our strong opposition," said Sun Weide, spokesperson for the Beijing Olympics organizing committee. "In terms of assembly and demonstrations, China has related laws and regulations. We hope that foreigners will respect the related Chinese laws and regulations."

A group of foreigners held another demonstration took place Wednesday morning at Tiananmen Square.

Three Americans spent about an hour at the iconic square criticizing China on a range of issues, from forced abortions to the banned Falun Gong spiritual movement.

The trio also set up a banner that said "Christ is King" and knelt and prayed.

Security concerns

The protests, while all non-violent, raised concerns about whether Olympic security was as tight as Chinese authorities claimed it to be.

Security for Beijing includes over 100,000 anti-terror military and police personnel, surface-to-air missiles and sophisticated satellite surveillance.

Beyond the visible military and police presence there is an estimated half a million volunteers working for the Chinese government to report suspicious behaviour or protests.

Beyond the normal security concerns for the Olympics that has existed since the killing of Israeli athletes in Munich, Germany in 1972, China faces a number of potential threats.

China's human rights record, particularly in regard to its treatment of Tibet and the crackdown in March on anti-government riots, has been the subject of most of the protests that plagued the torch run since it began in Athens, Greece on March 24.

On Monday, 16 Chinese police officers were killed in a terror attack the country said was committed by Uighur separatists - Turkic-speaking Muslims who support of the creation of an independent state of "East Turkistan."

But Canada's flagbearer told CTV News that he has no concerns about his personal safety.

"Absolutely not, I feel very safe," kayaker Adam van Koeverden said.

Some of the security restrictions in Beijing have taken visitors by surprise.

At Beijing's Olympic Park, the gates make notice of the restrictions applying to visitors. There is the obvious -- no guns, ammo or daggers -- but items such as umbrellas are also banned.

Beijing has also enacted a "no kite-flying" rule for the city.

Former Olympian's visa denied

Former Olympic speedskater Joey Cheek, who won gold in 2006, had his visa revoked by China Wednesday.

The decision came just hours before the American was set to travel to Beijing for two weeks to promote his effort to push China into helping peace efforts for the war-torn Darfur region of Sudan.

Cheek is the president and co-founder of Team Darfur, a collection of Olympic athletes working for peace in the region.

Cheek told CTV Newsnet when he asked the Chinese consulate why his visa was revoked he was told that "they didn't have to give a reason."

"I'm certain it's because of my involvement with Team Darfur," he said Wednesday.

He said that Team Darfur has 72 athletes competing in Beijing.

"With me not be able to go, it's a small example of a global effort by the Chinese to silence any kind of dissension at all," Cheek said.

More than 200,000 people have been killed and 2.5 million displaced in the fighting in Darfur that broke out in 2003. China is a major trading partner with Sudan.

Flame tours Beijing

The flame, which was carried from the Forbidden City early Wednesday, will now tour Beijing before arriving at the opening ceremonies on Friday.

Chinese basketball star Yao Ming was the first to carry the torch on Wednesday and was met by rapturous crowds in the capital city. China's first astronaut in space, Yang Liwei and movie director Zhang Yimou will also carry the torch.

"I'm very happy to be here," said Yang before the relay kicked off from the Forbidden City.

"That the torch is finally in Beijing is a realization of a dream we've had for a hundred years."

With a report from CTV's Lisa LaFlamme in Beijing and files from The Associated Press