Thousands of Ukrainian police have converged on a protest camp on Independence Square in the Ukrainian capital, Kiev.
Riot police and interior ministry officers have dismantled the biggest barricades - but met resistance from protesters.
The demonstrations began last month after President Viktor Yanukovych decided to withdraw from a free-trade deal with the European Union in favour of closer ties with Russia.
The latest police action comes after EU foreign policy chief Catherine Ashton held talks with President Yanukovych yesterday.
Mrs Ashton also met opposition leaders and visited the demonstrators in Independence Square, where she received a warm welcome.
Riot police and interior ministry officers have dismantled the biggest barricades - but met resistance from protesters.
The demonstrations began last month after President Viktor Yanukovych decided to withdraw from a free-trade deal with the European Union in favour of closer ties with Russia.
The latest police action comes after EU foreign policy chief Catherine Ashton held talks with President Yanukovych yesterday.
Mrs Ashton also met opposition leaders and visited the demonstrators in Independence Square, where she received a warm welcome.