Three militants of the outlawed Kurdish Workers' Party (PKK) were killed by Turkish security forces in a clash in the southeastern Turkish province of Sirnak, local newspaper Zaman reported on Monday.

The paper quoted a written statement of the Sirnak province as saying that three PKK members and one Turkish soldier were killed in Sunday's clash in the Bestler Dereler region of Sirnak.

Military operations in the area were continuing, the report added.

Violence in Turkey's mainly Kurdish southeastern regions has increased in the past few months, as about 40 PKK members and at least 14 Turkish soldiers and four police officers have been killed in clashes in the region.

In addition, recent pro-PKK Kurdish demonstrations in southeastern provinces and Istanbul claimed 17 more lives.

The Turkish authorities have vowed tough actions against the Kurdish rebel group.

"As long as the PKK exists, our operation will continue in ever- increasing intensity," said Gen. Yasar Buyukanit, commander of the land forces, in an interview with CNN-Turk television on Sunday.

In the last three years, about 410 PKK members and 260 Turkish security members have been killed in the clashes between the two sides.

More than 30,000 people have lost their lives since the PKK launched an armed campaign against the Turkish government for an independent Kurdish state in southeast Turkey in 1984.

Source: Xinhua