Ukraine crisis explained in 90 seconds

Efforts are under way to defuse tensions in the Ukrainian capital Kiev, where riot police have been deployed on Independence Square, still occupied by thousands of anti-government demonstrators.

President Viktor Yanukovych says he is willing to take part in round table negotiations with the opposition; protesters are demanding the resignation of the government and fresh elections.

BBC Online's Europe analyst Laurence Peter explains the context of the crisis.

Video produced by Michael Hirst