An Iranian protester taking part in a demonstration outside the French Embassy on Tuesday set himself afire, police said.
Police put out the flames and said the 38-year-old man was hospitalized in serious condition. They said his injuries were not life-threatening and did not release his name.
Some of the other 50 to 60 demonstrators received medical treatment at the scene for slight burns, believed to have been caused when they were trying to put out the flames, the police said.
The demonstrators, opponents of the current Tehran regime (search), were protesting Paris raids earlier in the day by French police who rounded up 165 members of the People's Mujahedeen of Iran (search), an Iranian opposition group accused of terrorism by the United States and the European Union.
The Mujahedeen regard themselves as legitimate opposition to the hardline regime in Tehran and their supporters have been campaigning to get the group removed from terrorism lists.
The French interior minister said the raids in Paris were motivated by evidence that France was becoming a major operations center for the group, whose Iraq-based military wing was disarmed by U.S. forces.
Police also seized $1.3 million in American currency, and large quantities of computer material and sophisticated transmission systems, an investigator said on condition of anonymity.
Ali Safavi, of the opposition National Council of Resistance for Iran (search), an umbrella group that includes the Mujahedeen, said the man who set himself on fire in London "was very shocked and angered by the French action."
Safavi called the French raids "unjustifiable, unwarranted, politically, morally and ethically unjustifiable .... only designed to mollify the Iranian regime."
The United States has publicly endorsed anti-government student demonstrations in Tehran that continued for an eighth straight day Tuesday.