French President Jacques Chirac on Friday led the condemnation of the violence that resulted in a shooting death after 100 Paris Saint-Germain fans attacked a supporter of an Israeli club on the previous day.
Police said a plainclothes officer shot at the PSG fans -- killing a man and wounding another -- when he went to the aid of a Hapoel Tel Aviv fan after a UEFA Cup match late Thursday.
The prosecutor's office identified the dead man as 24-year-old Julien Quemener.
The officer, Antoine Granomort, was being held in custody on Friday.
"They were shouting `filthy Jew' and when they saw our colleague, who comes from the Caribbean, they also yelled, `filthy black, we're going to get you," said a police union official, Luc Poignant.
Chirac condemned the racist remarks as "shameful."
They "inspire a feeling not only of condemnation, not only of stupefaction -- but also of horror," Chirac said at a summit meeting in Italy.
Police said the two men who were shot were members of PSG's far-right fan base that has a notorious violent and racist history.
Interior Minister Nicolas Sarkozy said some PSG fans shouted "Death to the Jew" as they attacked the Hapoel fan, whom officials said was French.
The police officer initially responded with tear gas, but was knocked to the ground by a blow to the head and kick to the stomach, Sarkozy said.
He then drew his handgun and opened fire.
"Two men fell to the ground, of which one died from his wounds, while the other suffered a lung injury," Sarkozy said.
Paris prosecutor Jean-Claude Marin said the PSG supporters had made Nazi salutes and shouted, "Le Pen, president," a reference to Jean-Marie Le Pen, leader of the extreme-right National Front party.
On Friday, Le Pen accused Marin of "complicity in defamation" and warned that his party would sue anyone who links it with the incident.
The police officer and the Hapoel fan eventually sought refuge in a nearby fast-food restaurant until police reinforcements arrived, officials said.
The Paris prosecutor's office and the National Police General Inspection unit, which probes incidents involving law enforcement officers, were investigating, police said.
While Britain has had considerable success in eradicating racially based violence, tougher punishments for hooligans have failed to solve the problem in France, despite repeated vows by Sarkozy and other politicians.
Paris Mayor Bertrand Delanoe said he would contact the capital's police chief and PSG president to discuss new measures.
"The seriousness of this event confirms the absolute necessity of fighting racism and anti-Semitism among PSG fans," Delanoe said in a statement. "I want to make sure that Paris' image and values are respected under every circumstance -- there is no room for the slightest form of intolerance."
French Sports Minister Jean-Francois Lamour denounced the "climate of tension and violence at certain soccer matches" and said the incident was "unacceptable and tainted the image of sports."
Paris lawmaker Claude Goasguen demanded that hooligan groups be disbanded.
The incident "shames soccer, shames PSG and shames Paris," he said.
Overt racism has become increasingly common at PSG's Parc de Princes stadium, with insults and monkey chants often directed at black players. Hooligan gangs also often look to fight black and Arab members of multiethnic rival gangs at the stadium during games.