Seven police officers have been killed in an explosion caused by a bomb-laden car in the mainly Kurdish city of Diyarbakir in south-east Turkey.

Twenty-seven people were injured, including 13 police officers, the local governor's office and police force said in a joint statement.

The statement said separatist "terrorists", a government designation for Kurdish militants, targeted an armoured vehicle transporting police personnel who had been temporarily deployed to the city.

The blast damaged several cars and shattered almost all the windows of a high-rise building in the area.

At least six ambulances deployed to collect casualties and security forces rushed to seal off the area.

The attack comes one day before Turkish Prime Minister Ahmet Davutoglu is due to visit the city, including the historic Sur district where a some neighbourhoods are under curfew.

Turkey has been imposing curfews in several districts of the south-east since August to flush out militants linked to the outlawed Kurdistan Workers' Party, or PKK. The Kurdish rebels have set up barricades, dug trenches and planted explosives to keep security forces at bay.

The military operations have raised concerns over human rights violations and scores of civilian deaths. Tens of thousands of people have been displaced in the fighting.