A gunman has opened fire in southern Turkey, killing four people, local media report.

Another eight people were injured in the Tarsus district, Mersin province, according to Turkey's Hurriyet newspaper and CNN Türk.

Monday's shooting is reported to have started at a restaurant, and the suspect - who is reported to be a 17-year-old youth - then fled in a car.

Police - using helicopter support - have launched a large-scale operation to apprehend the gunman.

Turkish media reports say two people were killed in the restaurant. They are believed to be the owner and an employee.

The gunman then continued shooting, killing a shepherd grazing his sheep nearby and a lorry driver.

The suspect's motives were not immediately known.