One Turkish soldier and two suspected members of the outlawed Kurdistan Workers' Party (PKK) were killed on Wednesday in clashes in the  southeast that erupted when the Kurdish rebels attacked a military post, the army said.

Militants launched an attack with guns and rockets on the command post in the village of Ozekli outside the southeastern city of Diyarbakir, the army said.

Turkish President Recep Tayyip Erdogan on Wednesday vowed to fight on against Kurdistan Workers' Party (PKK) militants, in the face of mounting attacks on security forces blamed on the Kurdish rebels.

"Let me put it clearly, the operations will continue," he said in a televised speech in Ankara, as Turkey presses on with air strikes on PKK targets in the country's southeast and in northern Iraq. 

Turkish authorities on Wednesday detained at least a dozen suspected members of the Islamic State (IS) jihadist group amid rising concerns about security throughout Turkey in an escalating cycle of violence.

Police detained the militants in coordinated dawn raids in the capital Ankara, as well as Istanbul, Hatay province near the Syrian border and the central Anatolian province of Kirikkale, the official Anatolia news agency reported.

President Barack Obama's administration vowed to press ahead with a half-billion-dollar mission to train Syrian opposition fighters Tuesday, despite fears that its initial failures have dented U.S. credibility. 

After the routing of a 54-strong U.S.-trained force by al-Qaida allied rebels, Pentagon spokeswoman Commander Elissa Smith told Agence France Presse there was no plan to pause or scale back the program.

President Recep Tayyip Erdogan on Tuesday vowed that Turkey would press on with a campaign against Kurdistan Workers Party (PKK) militants "until not one terrorist remains."

"We will continue our fight until weapons are laid down... and not one single terrorist remains within our borders," Erdogan said in a televised speech in Ankara.

A major conservative Islamist rebel group in Syria announced its support on Tuesday for a joint U.S.-Turkish plan to establish a border zone free of the jihadist Islamic State group.

The powerful Ahrar al-Sham rebel faction said the IS-free zone, planned along a stretch of border in the northern province of Aleppo, "is in the interest of the Syrian people".

Two prosecutors behind a graft probe that targeted the inner circle of Turkish President Recep Tayyip Erdogan fled to Armenia via Georgia after an arrest warrant was issued against them, officials said Friday.

The Istanbul prosecutor's office on Monday ordered the arrest of Zekeriya Oz, Celal Kara and Mehmet Yuzgec on accusations of "forming an organization to commit crime" and "attempting to overthrow the government by force".

Turkish warplanes Tuesday carried out a new wave of air strikes against Kurdish militants in the southeast of the country in retaliation for a day of bloody attacks that left six members of the security forces dead.

The military bombed 17 targets of the outlawed Kurdistan Workers' Party (PKK) in the southeastern Hakkari province, destroying them all, the army said in a statement.

Iranian Foreign Minister Mohammad Javad Zarif on Tuesday postponed a scheduled visit to Turkey, officials said, with mystery surrounding the reason for the last-minute cancellation.

The visit had been expected to touch on the Syria crisis, which has caused profound disagreements between Tehran and Ankara with Iran one of the last allies of Turkey's arch foe President Bashar Assad.

Social Affairs Minister Rashid Derbas has said that Lebanon should benefit from a decision by al-Qaida-linked al-Nusra Front in Syria to withdraw from areas along the border with Turkey.

The move by al-Nusra Front came two weeks after Turkey began carrying out airstrikes against Islamic State group targets in Syria. Turkey also agreed to allow U.S. warplanes to use the strategic Incirlik Air Base for operations against IS in Syria.