May 2, 2007 - 15:15 AMT
17 thousand policemen dispersed rally in Istanbul
Nearly 600 people have been arrested in Istanbul as police launched a dramatic clampdown on left-wing demonstrators trying to hold a May Day rally.

17 thousand policemen fired tear gas and used batons to stop the crowd marching to Taksim Square, where they were due to mark the 30th anniversary of "Bloody May Day".

Thirty-four people died in 1977 after a gunman fired, triggering a stampede.

This year's rally is taking place in a country already tense over a disputed presidential election.

The constitutional court is currently examining an opposition call to cancel the election of Foreign Minister Abdullah Gul as president. The first round of parliamentary voting ended in disarray on Friday.

After some violent clashes in one area of the city, a handful of trade union leaders were allowed into the square to lay red carnations in memory of those who died in 1977.

But police stopped television crews setting up satellite dishes in the square - one channel did however film events from a nearby building.

Meanwhile, public transport was paralyzed, as the authorities sealed off main roads, cancelled ferries and closed underground stations

Although the march was not specifically linked to the ongoing tension over the election, correspondents say some protesters raised their fists and called for the resignation of Prime Minister Recep Tayyip Erdogan - who supports Mr Gul as president, BBC reports.