Violence in the three-decade war with Kurdistan Workers Party 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 that he said had killed more than 3,000 militants in 2015.
A 35-year-old mother of three children was killed and another person was wounded on Sunday after a mortar hit their house in the district of Sur in the region's largest city of Diyarbakir, the 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 after they attempted to venture out of their home, the sources added.
A member of a special police unit in Sur was shot in the head today, security sources said. On Sunday, a soldier was killed in a bomb attack by members of the outlawed PKK in Sur, the General Staff said in a statement today.
Sur, which boasts UNESCO World Heritage sites, has been under a round-the-clock curfew since December 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.
The military said on Monday 225 PKK fighters have been killed in Silopi and the nearby town of Cizre since operations began in both places on December 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 supports 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, carrying homemade white flags on sticks, fled their houses, carrying their children and carting belongings in a wheelbarrow or suitcases.
One man told Reuters TV that he and family members were leaving, because they are unable to find medicine to prevent his disabled daughter's seizures.
"Every day they fire artillery and mortars," he said, without giving his name. "We must leave, but we don't know where we can go, how to leave."
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.