FACTBOX: The Olympic torch: peace, fraternity and controversy

(Reuters) - Security officials extinguished the Olympic torch at least twice on Monday during a chaotic relay through Paris where thousands of pro-Tibet protesters tried to block its path.

Here are some facts about the Olympic torch relay, and past and present controversies.

HISTORY OF THE FLAME:

* Flame races were run in ancient Athens to honor deities including Prometheus, who, legend has it, stole fire from the gods and brought wisdom and knowledge to humankind.

* A fire was kept burning at ancient Olympics to honor the sun god Zeus; but such races were not organized for the Panhellenic Games (four separate sports festivals of which the four-yearly Olympics were one).

* Fire first reappeared at the modern Olympics in Amsterdam in 1928, when a flame was built into an Olympic stadium tower. It was seen as a symbolic link between old and new games.

MODERN TORCH RELAYS:

* Foot races with torches were run at the 1894 international congress in Paris which decided to re-establish the Games.

* The first modern Olympic torch relay was introduced for the 1936 Berlin Games. More than 3,300 torchbearers carried the torch 3,190 kilometers (1,980 miles) from Olympia to Berlin.