MOSCOW -- A powerful explosion last night destroyed the headquarters of the Soviet Union's major anti-Communist opposition movement in what appeared to be the first political bombing in the capital in more than a decade.
No one was injured in the blast, which occurred just after 10:20 p.m. in the old brick building occupied by Democratic Russia a few hundred yards from the Kremlin. One activist, Alexander Fonyakin, was in a back room at the time and leapt from a ground-floor window when the explosion occurred. Neighbors said he was not hurt.
Apparently destroyed by the explosion were thousands of signatures on petitions necessary for registration of the candidacies of Boris N. Yeltsin for Russian president and Gavriil K. Popov for Moscow mayor. Both men, front-runners in the June 12 elections, are former Communists and present leaders of Democratic Russia, an umbrella movement encompassing all the major non-Communist parties and several other public organizations.
Also destroyed were petitions calling for a referendum on nationalization of the property of the Communist Party, an initiative bitterly opposed by the ruling party.
"It's a warning to us," said Viktor A. Kuzin, a radical member of the Moscow City Council, gazing at the wreckage created on a quiet street. "It's a sign that they are ready to do anything, including the physical annihilation of their opponents."
Who are "they"? "The Communist Party elite that was and still is in power in this country," Mr. Kuzin said.
Igor Kharichev, a member of Democratic Russia's coordinating council, said the council was meeting in the City Council building about a mile away last night when it received word of the blast. He said the group's Commission on Political Extremism had held a meeting in the headquarters the night before.
"I don't think this was done without the involvement of the KGB," Mr. Kharichev said. He offered only circumstantial evidence: the apparent professionalism of the bombers and the similarity of the circumstances of the explosion to recent bombings in Latvia and Lithuania in which many citizens suspect the KGB and army of involvement.
Activists said the petitions probably would not be too difficult to replace by Monday's deadline, because the candidates and cause they represent are so popular.
A total of 100,000 voters' signatures are necessary to nominate a presidential candidate, 35,000 for a mayoral candidate and 1 million to force the referendum on party property.
Mr. Kharichev said initial reports suggested that someone before or after the blast may have stolen Democratic Russia's card file, recording the addresses and telephone numbers of several thousand local units and activists.
"That's a significant loss," he said, though the information eventually could be restored.
Witnesses said an inspector from Mosgas, the city natural gas concern, visited the premises late last night and ruled out a natural gas leak. They said firemen who were among the first on the scene reported a strong smell of ammonal, an explosive.
At 1 a.m., police officers, firefighters and KGB bomb specialists were picking through the rubble under the glare of two powerful spotlights. It appeared that the bomb had been placed inside the front door of the one-story building.
Rubble littered Staromonetnaya Street, across the Moscow River from the Kremlin, for about 50 yards. A large piece of the metal roof, blown off and twisted by the blast, hung in front of where the door had been.
Windows were blown out on lower floors of nearby buildings -- including a police station just across the street. Witnesses said a police car had passed by moments before the bomb exploded.
Despite the stormy politics of the last few years, there have been relatively few terrorist bombings in the Soviet Union except for those related to interethnic violence in Central Asia and the Caucasus.
Democratic Russia activists said the last political bombing in the capital they could recall was an explosion in the city's metro in 1977 that killed seven people and wounded 44 others. Three Armenian nationalists were found guilty and executed, despite the public statement of human rights activist Andrei D. Sakharov that he believed the KGB had planted the bomb.
About two years ago, the KGB said it found another, unexploded bomb on the Moscow metro.