In the latest trouble, rioters set fire to banks and stoned shops in the town of Kiziltepe.
Special police unions moved in with tear gas.
One person was killed and 16 others were injured.
The clashes erupted on Tuesday after funerals for 14 members of the outlawed separatist group, the Kurdistan Workers Party (PKK), killed last week in clashes with security forces.
Turkish Prime Minister Tayyip Erdogan accused the rioters of trying to split the country.
It's the worst violence in the predominantly Kurdish region for years and has raised fears of a renewed separatist struggle in Turkey, damaging the country's efforts to become a member of the European Union.
The EU has expressed concern about the plight of the Kurds and has urged Turkey to do more to combat poverty and ease cultural restrictions in the south-east of the country.