One of the dead at the hospital in Diyarbakir, the biggest city of the country's mainly Kurdish southeast, was a 78-year-old man who doctors said was struck during the clashes, the official added.

The second was an 18-year-old man.

It was not immediately clear when the two were admitted to hospital.

They were the latest victims of a wave of rioting that began in Diyarbakir last Tuesday and rapidly spread throughout the region and later to Istanbul, Turkey's biggest city.

Three people were killed in Istanbul late Sunday when a group of protestors hurled a Molotov coctail at a city bus, setting it ablaze.

An elderly woman fleeing the burning vehicle was hit by a car and died in hospital.

Two more bodies were recovered after police removed the wreckage of the bus, which crashed into a truck.

Of the 12 people killed in southeastern Turkey, three were children.

Dozens of others -- mostly members of the security forces -- have been injured in this region's most serious outbreak of civil disorder in a dozen years.

The situation was calm in Diyarbakir on Monday, an AFP journalist there said, while sporadic clashes continued in nearby Kiziltepe and Nusaybin, on the border with Syria, where 58 people were arrested, the local governor said.

Violence in Turkey's Kurdish southeast has escalated since June 2004, when the outlawed Kurdistan Workers' Party (PKK) ended a unilateral ceasefire it had proclaimed five years previously.

The PKK has waged an armed separatist campaign against the government since 1984 in a conflict that has claimed more than 37,000 lives.