Protest and controversy have surrounded the Beijing [Images] Olympic flame since it was lit in Greece two weeks ago -- and so has a phalanx of large and physically fit Chinese men in blue and white track suits.

The hand-picked team of crack security operatives look like a cross between marathon gold medalists and secret service agents, trotting beside the flame with stern faces and earpieces, along the most ambitious torch route ever attempted, dubbed by Beijing the "Harmonious Journey".

The flame is supposed to symbolise peace and unity and the relay is meant to be a celebration, but the run has sometimes resembled an obstacle course, with activists lunging for the flame, throwing water and trying to aim fire extinguishers at it.

The Chinese security guards -- who in Paris nervously turned the flame off several times on Monday and retreated with the torch to a bus when protesters advanced -- have drawn fire for their heavy-handed approach to managing the torch's progress.

In London [Images], Sebastian Coe, chairman of the 2012 Olympics [Images] organising committee and a two-time Olympic gold medalist, called them "thugs", British media reported.

Torch bearer and former Blue Peter presenter Konnie Huq described them as aggressive.

"They were very robotic, very full on, and actually I noticed them having skirmishes with our own police and the Olympic authorities before our leg of the relay, which was confusing," she was quoted as telling BBC Radio 4.

"They were barking orders at me, like 'Run! Stop!', and I was like, 'Oh my gosh, who are these people?'," the Daily Mail quoted her as saying. "They kept pushing my hand up higher when I was holding the torch, so they were...interesting."

Australian Prime Minister Kevin Rudd said Australia, not China, would provide security for the flame when it heads there later this month, but The Age reported there were still plans for Chinese "torch attendants" to accompany it through Canberra.

So just who are these men in the track suits?

Employed by the Beijing Olympic Organising Committee (BOCOG), the "flame protection squad" was formed in August 2007 to safeguard the fire 24 hours a day on its 137,000-km (85,130-mile), 130-day relay, state media have reported.

Its members were picked from the ranks of the People's Armed Police, the security force spun off from the army that is responsible for riot control and domestic stability. Tens of thousands of "wujing", as they are called in Chinese, have been deployed to Tibet [Images] and neighbouring areas to quash recent unrest.

"These men, chosen from around the country, are each tall and large and are eminently talented and powerful," their leader Zhao Si was quoted as saying. One online report said the shortest among them stood 1.9 metres tall.

"Their outstanding physical quality is not in the slightest inferior to that of specialised athletes," Zhao said.

The squad is divided into two teams: one with 30 members accompanies the torch on its international leg, and the other, with some 40 guards, protects the flame on its run through every Chinese province and region until it arrives in Beijing to start the Games on Aug. 8.

"Following the torch and protecting it is hard work, some of the team members will run 40-50 km a day," one article said.

To prepare, the flame security agents-in-training ran at least 10 km per day on mountain roads, said an article posted on a government Web site, www.china.com.cn. These ironmen also underwent training in local customs and languages, including English, French, German, Spanish and Japanese.