The gunman, armed with an assault rifle, opened fire on the crowd holding a protest march in Bulanik town, in the mainly Kurdish province of Mus, denouncing the banning of the Democratic Society party (DTP), the town's mayor Ziya Akkaya told the NTV news channel.

The police detained the assailant, Anatolia news agency reported.

Akkaya initially said "seven or eight people" were wounded in the incident, but brought the number drown to six in a later broadcast.

The shooting came after the protestors stoned shops and banks along the route of the march and harassed shopkeepers who had not closed their stores in protest at t ban on the DTP, media reports said.

Anatolia said the windows of the gunman's shop were broken and his vehicle torched by the protestors.

Closing shops is a traditional Kurdish protest method against the state and shopkeepers who refuse to do so are said to come under pressure from militant Kurds.

Television footage showed a crowd of several hundred people marching through the town and some pelting an armoured police vehicle with stones.

There have been daily protests in the Kurdish-populated southeast and east of Turkey -- as well as major western towns with large numbers of Kurdish migrants -- since Friday when the constitutional court banned the DTP.

The court said the DTP had become a "focal point of activities against the indivisible unity of the state, the country and the nation" through its links to Kurdish rebels waging a 25-year insurgency for self-rule in the southeast.

The ban undermined a government drive, launched in August, to expand the rights of Turkey's estimated 12 million Kurds in the hope of ending the armed campaign by the outlawed Kurdistan Workers' Party (PKK).