Istanbul Governorship halted all roads and public transportation leading to Taksim Square, where workers' unions and NGO's aimed to hold the rally to commemorate the 30th anniversary of May Day 1977.

In that day, more than 500 thousand had gathered when unidentified people fired on the crowd leaving 34 people dead.

Authorities had declared the area off limits to protesters but allowed a few hundred of them to lay red carnations at the square. It was the first time authorities allowed some May Day protesters, including union officials, to enter the square since the 1980 military coup. Police did not allow hundreds of others to reach the square.

The blockage brought the traffic nearly to halt in all parts of the city and people stayed on roads for hours.

Police also stopped television crews setting up satellite dishes in the square, although one channel filmed events from a nearby building.

"Martial law at hand"

Turkey's Confederation of Revolutionary workers' Unions (DİSK) revealed that anti-terror police attacked the crowds from early morning with tear gas and batons.

Mayor Guler said the number of arrests exceeded 500 by noon.

DİSK lawyer Necdet Okcan told bianet that security forces stopped busses coming from other cities at Istanbul borders and forced them to return back.

It's reported that four busses were attacked by tear gas and all were taken under custody. Some of the injured by police intervention are under treatment in hospitals.

Looking at the situation, one can think that the mayorship executes martial law, Okcan said.

There's no law preventing people from peaceful rallies but the police and the authorities de facto limit such attempts.(EÜ)