Pro-Tibet freedom protesters from media rights group Reporters Without Borders broke through the cordon of 1,000 police officers in Olympia, Greece, as China's envoy spoke and the Olympic torch was lit prior to the Beijing games.
Human rights and free speech activists had vowed to protest over the violence in and around Tibet at the ceremony, saying that it was a mockery of the symbolism of human unity when the Games' sponsors were flagrantly suppressing human rights.
The famous torch was lit in spite of the disruption, will be carried around Greece before being sent to China to start a journey through 20 countries, returning to Beijing on 8 August 2008.
"The torch is the link between all athletes and citizens of this world... It has the force to unite humanity and to stand for harmony", said Jacques Rogge, IOC President.
The route agreed includes the torch being taken to the top of Mount Everest and through Tibet.
As Liu Qi, head of the Beijing Olympic organising committee, spoke ahead of the torch lighting, three men broke into the ceremony venue.
One ran up behind him attempting to display a black flag depicting the Olympic rings made from handcuffs.
The men were from the France-based media rights watchdog Reporters Sans Frontieres (Reporters Without Borders, or RSF), which has called for a boycott of the opening ceremony of the games.
Protesters were quickly bundled away by police and Mr Liu continued his speech, reports the BBC.