Turkish Prime Minister Tayyip Erdogan yesterday called for national unity after a court ban on a Kurdish party caused angry protests and plunged the country into political uncertainty.

The court ruling drew criticism from the European Union, dealing a new blow to Turkey's faltering hopes of EU membership.

In Diyarbakir, the largest city in the southeast, thousands of Kurds took to the streets watched by riot police during a fourth day of protests since the court disbanded the only Kurdish party in Parliament.

In the town of Dogubeyazit, angry protesters threw petrol bombs and stones at police, who fired back with tear gas and water cannon.

Clashes have erupted mainly in villages in the southeast, but also in the heart of Istanbul's shopping and entertainment district on Sunday, raising ethnic tensions.

The European Commission yesterday warned that the verdict could deprive a substantial portion of Turkish voters from representation, which it said was essential to Ankara fulfilling its democratic mandate.

The ruling AK Party wants to push reforms aimed at ending decades of conflict with Kurdish separatists and, in his first comments since the verdict was delivered, Prime Minister Erdogan spoke of the need for a national sense of determination.

"We will overcome these problems as long as our nation is united and in solidarity," Mr Erdogan told reporters in Ankara.

Investors who are hardened to the emerging market's domestic turmoil were relatively untroubled by the events.