Several hundred people are protesting for a second day in the Ukrainian capital Kyiv, after parliament passed a bill that would make Russian an official regional language in mainly Russian areas of Ukraine.

The bill was pushed through parliament Tuesday by supporters of President Viktor Yanukovich, who draws his support from the Russian-speaking east. The western part of the country speaks Ukrainian and is fervently nationalistic.

Parliament Speaker Volodymyr Lytvyn later announced his resignation, saying the vote was illegitimate. Some opponents of the measure have announced hunger strikes.

On Wednesday, clashes erupted outside a government building in the center of the city.

Jailed former prime minister Yulia Tymoshenko has urged her supporters to protest the law. Opponents say the measure could threaten the country's sovereignty after 20 years of independence from the former Soviet Union, and would effectively phase out the Ukrainian language.