CHISINAU, Moldova  On Wednesday, Moldova’s Parliament building was seared black from fire, and its ceremonial entryway was spray-painted with crossed-out hammers and sickles. Filing cabinets lay where they crashed to the ground the night before, while office papers were tangled in the boughs of pine trees.

Ruslan Grosu, 21, stood outside, trying to make sense of it.

“A little revolution happened here,” he said. “There is this power in our youth, and they should respect our wishes.” But from inside the building came the bleak sound of workers knocking out broken windows, and Mr. Grosu felt compelled to add this: “Almost all of us think it is bad and evil, what happened here.”

“We are not thieves,” he said.

A day after a huge anti-Communist rally turned violent in Chisinau, Moldova’s capital, everyone was speculating about who was behind it.

Image Workers cleaning up in front of the parliament building on Wednesday. Credit... John McConnico/Associated Press

President Vladimir Voronin said the event had been planned by Romanians, and called for the Romanian ambassador to leave within 24 hours. Youth activists charged that opposition parties had hijacked an otherwise peaceful crowd for their own purposes. And the opposition leader Vlad Filat said authorities had allowed the protests to get out of hand in order to portray the president’s challengers as extremists.