Russia's lower house of parliament, the Duma, has approved a partial amnesty for Chechen separatists who disarm and for Russian servicemen accused of committing crimes in Chechnya. President Putin has said the amnesty will help restore peace in the break-away region, but critics are not so sure. In a third and final reading Friday, the Duma voted 352 to 25 to offer amnesty to Chechen separatists and Russian federal forces, who have faced off in two Russian campaigns in Chechnya since the mid 1990s.

The amnesty, which takes effect within days, orders authorities not to punish separatist Chechen rebels who lay down their arms or renounce separatism by September 1. It also provides protection to Russian federal forces. According to Chechen civilians and human rights groups many Russian soldiers engaged in abuses.

Two Duma factions, the liberal opposition Yabloko and ultra-nationalists aligned with Vladimir Zhirinovsky, were opposed to the amnesty.

Russian news agencies quote Yabloko's Sergei Mitrokhin as saying the amnesty is nothing more than a presidential public relations stunt, which can not be translated into reality as long as the near daily violence continues in Chechnya. Mr. Zhirinovsky called the amnesty shameful.

Western human rights groups have also expressed outrage that the amnesty protects Russian soldiers accused of committing atrocities against civilians. And they expressed concern that it denies pardons to Chechen rebels who tried to kill Russian troops.

Presidential aide Sergei Yastrzhembsky suggested Friday that the ongoing violence in Chechnya and neighboring regions is aimed at stalling the government's peace effort.

Mr. Yastrzhembsky said all such attempts are doomed to failure. He says the process of a political resolution to the decades-old conflict in Chechnya is irreversible.

The amnesty's approval comes one day after a female suicide bomber ambushed a bus carrying Russian Air Force officers and civilians in a region neighboring Chechnya, killing 20 people. It was the third such bombing in less than a month in the region and dealt yet another blow to President Putin's claims that life in the break-away republic is returning to normal.

In the early hours of Friday, an explosion ripped through a five-story apartment block in the Chechen capital, Grozny, killing at least 11 people. But government investigators say initial evidence points to a natural gas leak, not terrorism, as the cause of the blast.