Ukraine's Interior ministry says 67 police were captured in all, it was not clear how. An opposition lawmaker said they were being held in Kiev's occupied city hall.
President Viktor Yanukovych and the opposition protesters who are demanding his resignation are locked in an epic battle over the identity of Ukraine, a nation of 46 million that has divided loyalties between Russia and the West.
Parts of the country, mostly in its western cities, are in open revolt against Yanukovych's central government, while many in eastern Ukraine back the president and favour strong ties with Russia, their former Soviet ruler.
Protesters across the country are also upset over corruption in Ukraine, the lack of democratic rights and the country's ailing economy, which just barely avoided bankruptcy with a USD 15 billion loan from Russia.
At least 101 people have died this week in the clashes in Kiev, a sharp reversal in three months of mostly peaceful protests.
Today was the deadliest day yet at the sprawling protest camp on Kiev's Independence Square, also called the Maidan.
