MOSCOW - Russia's lower house of parliament gave final approval to a bill on combatting political extremism Thursday, but human rights advocates said it would deal a greater blow to liberal activism than to the radical nationalism suspected of inspiring recent hate crimes.

Lawmakers in the State Duma voted 275 to 145 to pass the bill in its third and final reading. The bill defines extremism as any activity aimed at overthrowing the government, instigating social, national or religious hatred, or distributing fascist literature.

Kremlin officials have said law enforcement agencies need new legal tools to deal with neo-fascist organizations and skinheads who attack racial and ethnic minorities. Police have long classified such attacks as simple "hooliganism."

Russia has seen a number of high-profile racist and anti-Semitic acts recently, including the April slaying of an Afghan interpreter by skinheads. Last month, a sign reading "Death to Jews" exploded in the face of a woman who tried to remove it from the roadside outside Moscow.

Opponents say the bill's definition of extremism is too broad and could allow police to close down activist organizations or hand out severe punishments to demonstrators who hold unsanctioned protests.

At the same time, the bill, which is expected to be passed by the upper house and signed by President Vladimir Putin, would have little effect on the many violent ultranationalist groups that have sprouted in Russia, critics say.

Alexander Verkhovsky, vice president of the Moscow-based Panorama research center, which has published several studies of extremist movements, said police already have enough tools to prosecute extremists - including laws against inciting ethnic conflict and advocating the violent overthrow of the government. Police and prosecutors simply look the other way at such crimes, he said.

Ironically, the bill could be used against people who study extremist movements or speak out against them, Verkhovsky said.

"The bill prohibits the use of Nazi symbols. I'm sure there's a swastika depicted somewhere in this book," he said, pointing to a Panorama publication presented Thursday titled "Naziism in Russia."

The book's author, Vyacheslav Likhachyov, said neo-Nazi movements have gained popularity because of the ideological vacuum left by the collapse of communism.

"You could say who a Soviet person was and what they should be proud of. But who is a Russian and what is he proud of?" Likhachyov said.

Lyudmila Alexeyeva, head of the Moscow Helsinki Group, a respected human rights watchdog, said that if Putin was serious about cracking down on extremism, he would have condemned recent statements against minorities by Krasnodar Governor Alexander Tkachyov and Duma vice speaker Vladimir Zhirinovsky.

About a dozen members of nationalist organizations - mostly young men with shaved heads - sat at the back of the room during the Panorama book presentation and flashed angry looks at Likhachyov until the moderator gave them the floor.

Semyon Tokmakov, a prominent neo-Nazi who was convicted of assaulting a black U.S. Marine in Moscow in 1998, said his beliefs were "the reaction of a healthy person to the Naziism of ethnic minorities."

Addressing Likhachyov and the other speakers, he said, "I see you are Jewish" and suggested they move to Israel.