DIYARBAKIR, Turkey Two civilians, two soldiers and a police officer have been killed in southeastern Turkey as military operations to root out armed fighters focused on urban centers across the mainly Kurdish region, security sources said.

A local court jailed the former mayor of the mainly Kurdish city of Van for 15 years, the maximum term for the crime of membership of the outlawed Kurdistan Workers Party (PKK).

Bekir Kaya, re-elected to a second term in 2014, had spent part of his first mayoral tenure in pre-trial detention on the charges, which were brought in 2012.

Violence in a three-decade-old war with PKK fighters flared in July after the collapse of peace talks. President Tayyip Erdogan said last week there would be no let-up in a military campaign he said had killed more than 3,000 militants in 2015.

A 35-year-old mother of three was killed and another person was wounded on Sunday when a mortar shell hit their house in the district of Sur in the region's largest city of Diyarbakir, the security sources said late on Sunday.

In the town of Silopi, east of Diyarbakir near the Syrian and Iraqi borders, a man was killed by gunfire and his wife and another relative were wounded when they attempted to venture out of their home, the sources added.

A soldier was killed in a gun attack in Sur on Monday, the General Staff said, hours after a member of a special police unit in Sur was shot dead, according to security sources. On Sunday, a soldier was killed in a PKK bomb attack in Sur.

Sur, which boasts UNESCO World Heritage sites, has been under a round-the-clock curfew since Dec. 2 as the army tries to push out PKK fighters who have dug trenches and built barricades there and in other residential areas in the region.

TANK FIRE

The military said 225 PKK fighters had been killed in Silopi and the nearby town of Cizre since operations began in both places on Dec. 14. Hundreds of soldiers and civilians have also died in towns and cities across the region in the operations.

Erdogan said at the weekend he supported a criminal investigation of the leaders of the Peoples' Democratic Party (HDP), a parliamentary group with Kurdish origins, over comments about self-rule.

In the town of Cizre, tanks could be seen pounding buildings believed to contain PKK members on Sunday, Reuters TV footage showed.

Local residents fled their houses, carrying their children and carting belongings in a wheelbarrow or suitcases.

The autonomy-seeking PKK took up arms in 1984, and more than 40,000 people - mainly Kurds - have been killed in the violence. The PKK is designated a terrorist group by Turkey, the United States and the European Union.

(Additional reporting by Melih Aslan; Writing by Ayla Jean Yackley; Editing by Ece Toksabay and Ralph Boulton)