An explosion tore through Russian republic leader Boris Yeltsin's campaign headquarters late Thursday in the first violence of the republic's presidential election campaign.

There were no injuries, but the front entrance to the building housing the Democratic Russia Movement was blown away. No one claimed responsibility for the bombing.Leonid Bogdanov, who is in charge of the Democratic Russia Fund, said the blast occurred about 10:20 p.m., destroying about 15,000 Yeltsin posters and $11,236 worth of campaign badges.

Police said the remains of a homemade explosive device were found, the independent Interfax News Agency reported. Bogdanov said it was a time bomb.