In the worst of the clashes, around 300 demonstrators attacked a police station in Mersin, on the southern Mediterranean coast, with stones and Molotov cocktails on Sunday evening, according to the NTV news channel.

A 16-year-old was shot in the chest and protesters burned shops in the town, which is home to a large Kurdish population, television reports said.

In Istanbul, demonstrators set fire to a bus in the Sultanbeyli district on the European side of the city, without injuring anyone, Anatolia news agency reported.

Police broke up a demonstration by young Kurds in the centre of Istanbul, according to the same agency, and violence flared in other Turkish towns with large Kurdish populations.

The PKK was founded in 1978 by Abdullah Ocalan, who has been serving a life sentence for treason and separatism since 1999, and the organisation is listed as a terrorist group by Turkey and much of the international community.

It took up arms in Turkey's mainly Kurdish southeast in 1984, sparking a conflict that has claimed about 45,000 lives.

The PKK has gone from seeking full independence for the Kurdish region to calling for regional autonomy and better cultural rights for Kurds.

Ankara has recently announced measures aimed at improving Kurdish rights in the hope of undermining support for the PKK.