More violence in the Turkish capital Friday as demonstrators clash with police for a fourth night.

Intermittent and less turbulent protests have taken place since the massive riots over the summer, but have intensified this past week after a protester was killed during clashes near the border with Syria.

The latest unrest comes just six months before local elections.

The summer protests presented one of the biggest challenges to Prime Minister Tayyip Erdogan's rule since his Islamist-rooted AK Party first came to power a decade ago.