"By uniting, we will close the door on terrorism and we will work as hard as we can to ensure that this country grows a little freer, more democratic, richer and happier every day," said Erdogan during a local conference held by his Justice and Development Party (AKP) in Diyarbakir, the region's capital.

The prime minister stressed the distinction between democratic protests, supported by the government, and violent acts, which the authorities would continue to punish.

"We in the government will respond robustly to terrorism but also determinedly pursue our efforts towards democracy and development," he told the gathered supporters in a heavily guarded stadium in Diyarbakir.

Erdogan cited the 21 new factories he was due to open over the course of the day as evidence of his commitment to the development of the region, one of Turkey's poorest.

Erdogan's comments came as the armed separatist PKK, which Turkey, the European Union and the United States consider to be a terrorist organisation, increased its operations against the security forces in the region.

In addition, the Kurdistan Freedom Falcons (TAK), a group the authorities link to the PKK, has claimed responsibility for several bomb attacks on towns in the west of the country since the beginning of the year.

Riots erupted in Diyarbakir in late March after youths demanding vengeance attacked the police following the funerals of PKK rebels killed in fighting with Turkish armed forces.

A total of 16 people, including three small boys, were killed when security forces opened fire and used tear gas to disperse crowds.

Three women were also crushed to death in Istanbul when Kurdish rioters set a city bus ablaze with a petrol bomb.

The Kurdish conflict has killed more than 37,000 people since the start of the PKK uprising in 1984.