Turkish officials say 12 people were killed after Kurdish separatists ambushed and opened fire on a bus in the south-east of the country.

Civilians and armed guards were said to be among the victims of the ambush.

The attack, in Sirnak province near the Iraqi border, followed the killing of a leader of the banned PKK or Kurdistan Workers Party.

On Friday Iraq and Turkey signed a security agreement aimed at curbing the activities of the banned PKK.