Ankara, Oct 9 (IANS/EFE): Kurdish demonstrations against Turkey's failure to stem the advancement of the Islamic State (IS) terrorist group in northern Syria continued overnight and at least 23 people died in the unrest, Turkish media reported Thursday.

Turkish authorities extended the curfew in the heavily Kurdish southeastern province of Diyarbakir until Friday and the local university was closed until Monday.

Despite the curfews, protests continued in several districts of Diyarbakir and in many other cities across the country.

In Istanbul, unidentified gunmen opened fire on a group of Kurdish demonstrators and many people were wounded, the Milliyet newspaper said in its online edition.

One of those wounded later died.

In the southern city of Adana, a man was stabbed to death during a fight after protesters asked him whether he was a member of the IS.

In Tarsus, a city in the province of Adana, a police vehicle was attacked by unknown assailants and four officers were injured.

In the same city, Islamist anti-Kurdish demonstrators burned the local headquarters of the pro-Kurdish People's Democratic Party.

During the three days of demonstrations, some 170 police officers have been injured in clashes with demonstrators.

In many cities, the Turkish army has deployed troops and armoured vehicles in a bid to control the protests.

Turkey's Kurds are demanding that the government go to the aid of the Syrian Kurdish city of Kobani, located on the border with Turkey, which has been besieged by IS for more than three weeks.

Turkish Prime Minister Ahmet Davutoglu warned protesters Wednesday that any vandalism would not be tolerated.

Meanwhile, new Secretary General of NATO, Jens Stoltenberg, arrived Thursday in Turkey where he will meet President Recep Tayyip Erdogan and the prime minister.

In a related development, the Turkish press reported Thursday an IS threat against Turkey through a message sent via Tweeter.

Turkey would pay a very high price for joining the international military coaltion crusade the IS, said the message, claiming that the jihadi group had thousands of sleeper cells in Turkey.