KIEV, Ukraine — As demonstrators in ski masks scuffled with the police here on Tuesday evening, opposition leaders accused the government of provoking the very violence it has been condemning in an effort to discredit and possibly split the protest movement.

“The government tried to marginalize the protest, hoping that after 60 days in the cold people would become tired and leave, and only a different contingent would remain, only bums, but this did not work,” said Yuri Syrotyuk, a deputy head of the nationalist Svoboda party and a member of Parliament.

“The government then decided to provoke a conflict, so some radical element would respond,” he added. “They wanted a schism. They are following the Roman principle of divide and conquer. This is their plan, but it will not work.”

Opposition leaders say the government of President Viktor F. Yanukovich has also rebuffed all offers of negotiations, adding fuel to a volatile situation.