Russia demands answers from Erdogan after call to topple Assad

The Kremlin has said it expects an explanation from the Turkish president after he said his forces were in Syria to topple Bashar al-Assad.

In a speech on Tuesday, Tayyip Recep Erdogan condemned what he said was the failure of the United Nations in Syria, and cast Turkey's incursion in August, when it sent tanks, fighter jets and special forces over the border, as an act of exasperation.

"We are there to bring justice. We are there to end the rule of the cruel Assad, who has been spreading state terror," Erdogan said.

"The announcement really came as news to us," Kremlin spokesman Dmitry Peskov said on Wednesday.

"It is a very serious statement and one which differs from previous ones, and with our understanding of the situation. We hope that our Turkish partners will provide us with some kind of explanation about this."

Previous reports by Middle East Eye have indicated that the Turkish incursion into northern Syria, which Ankara declared as an operation against Islamic State and Kurdish PKK militants, had been tacitly coordinated with the the Syrian government through Iranian interlocutors. The goal was to create a "safe zone" along the border roughly 90km inside Syrian territory and to force Kurdish militia groups back east of the Euphrates river. 

Turkish soldiers 'kidnapped'

The Turkish military said it lost contact on Tuesday with two of its soldiers deployed in northern Syria, although it stopped short of confirming an Islamic State claim that the group had kidnapped the pair.

The army said that contact was lost at around 3:30pm local time. It did not give any further details.

IS's Amaq news agency earlier said that IS fighters had captured two Turkish soldiers near the village of Dana west of al-Bab in the Aleppo countryside. Reuters was not immediately able to verify the authenticity of the claim.

IS is believed to have kidnapped a Turkish soldier near Turkey's border with Syria in the summer of 2015. His whereabouts are still unknown.

Turkey launched an incursion into northern Syria in August, sending tanks, fighter jets and special forces over the border.

Rebels have since then captured IS strongholds of Jarabulus, Al Rai and liberated the symbolically important town of Dabiq, without much resistance.

Backed by Turkey, they are now pressing to take Al-Bab, deeper inside Syria, from the militant group. 

On Sunday, the Turkish army said 22 Syrian rebels were hit by an IS gas attack in northern Syria. 

It was the first time Ankara has accused the group of chemical warfare.