DIYARBAKIR, Turkey (Reuters) - Three members of the Turkish security forces were killed on Saturday in clashes with militants in Turkey’s mainly Kurdish southeast, security forces said.

Hundreds of people have died since the Kurdistan Workers’ Party (PKK) abandoned its two-and-a-half-year ceasefire in July and the Turkish air force began striking PKK targets in northern Iraq.

Two gendarmes were killed when militants opened fire on their vehicle in the town of Cizre, near the Syrian and Turkish borders, officials said. Two others were wounded in the attack.

Security forces launched an operation in Cizre in pursuit of the attackers, shutting off entry and exit routes of the town. Witnesses said gunfire could be heard as residents fled indoors.

In Diyarbakir, the largest city in the region, a police officer was shot to death and another wounded during clashes.

A half-dozen neighbourhoods in the city are under a round-the-clock curfew as operations against the PKK continue.

Curfews in several districts in the nearby towns of Hazro and Lice in Diyarbakir province were also introduced on Saturday, the governor’s office said.

The autonomy-seeking PKK took up arms against the Turkish state in 1984, and more than 40,000 people, mainly Kurds, have died in the ensuing violence. Some 15 million ethnic Kurds make up Turkey’s largest ethnic minority.