Kyiv is expected to be the scene of large protest rallies this weekend, with demonstrators on the side of pro-Western President Viktor Yushchenko and his pro-Russia rival, Prime Minister Viktor Yanukovych, expected to gather -- and possibly clash. Yushchenko is threatening to call a snap election.

An excerpt from the BBC story:

The rally has been organised by the opposition. It claims the pro-Russian ruling coalition is illegally trying to seize power.

Recently a number of MPs who support the president have defected, with more expected to follow suit.

But the ruling coalition wants the president to back down from his threat to call an early election, and it is also holding a protest in Kiev on Saturday.

This will take place near the opposition rally and at around the same time.

Tensions are running high, and with thousands of protesters expected, there is concern that there may be violent clashes.