Turkish authorities had rejected a Kurdish demand to mark Navroz on Sunday as it was a holiday and had declared Wednesday as the official day for the festivities.

Police fired tear gas and used water cannons to prevent thousands of Kurds from gathering at the main square in Diyarbakir, the capital of the Kurdish-majority south, an AFP correspondent said.

But the crowd of more than 5,000 pressed on despite the police action and assembled at the city centre to mark Navroz.

Many wore clothes sporting the colours of The Kurdistan Workers' Party (PKK) -- green, red and yellow.

The banned PKK took up arms in Kurdish-majority southeastern Turkey in 1984, sparking a conflict that has claimed about 45,000 lives. It is labelled a terrorist outfit by Ankara and much of the international community.

In Istanbul, police prevented Kurdish groups from gathering at a venue where the country's main Kurdish party had organised festivities. They stoned the policemen, who had set up barricades, Anatolia news agency reported.

Police here too used water cannons and tear gas, Anatolia said.

Navroz celebrations are traditionally used by Turkey's Kurdish minority to press for greater rights and profess its allegiance to the PKK.