Protestors throw stones at riot police car during  May Day clashes in Istanbul, 01 May 2008

Thousands of Turkish riot police have broken up crowds of trade union members who gathered in Istanbul for a May Day rally banned by the government.

Police used water cannons, tear gas and clubs to disperse hundreds of workers who tried to reach the city's Taksim square in defiance of the ban. Some protesters threw stones at the police.

Several people were injured in the street battles and an unknown number of protesters were detained.

Turkey's main left-wing labor confederation, DISK, later abandoned its plan to rally in Taksim square because of the police resistance.

Turkey's government banned May Day gatherings in the square, fearing they could turn violent. Trade unions are angry with government plans to reform social security by raising the retirement age.

The unions wanted to gather in Taksim square to commemorate the killing of 37 people there during a May Day rally in 1977.

May Day rallies also were held today in Russia. Authorities say around 30,000 people joined several marches in the capital, Moscow. The city's largest rally was organized by the ruling United Russia party of outgoing President Vladimir Putin.

In far eastern Russia, crowds protested against soaring food prices and cuts in social welfare spending.

Elsewhere, several hundred opposition activists planned to march in St. Petersburg. The holiday has lost much of its significance for many Russians since the end of the Soviet era, when May 1 was a major celebration of worker solidarity and Soviet might.

Some information for this report was provided by AFP, and Reuters.