Fighting Kurdish militia in Syria is 'legitimate defence': Erdogan

Turkish President Recep Tayyip Erdogan on Sunday defended his country's fight against Kurdish fighters in Syria as a "legitimate defence," dismissing calls from international powers to rein in Ankara's cross-border bombardments.

Turkey has been shelling targets in northern Syria for the past week in a bid to stem the advances of a Kurdish-led coalition, the Syrian Democratic Forces, that has seized territory in the area.

Ankara blames Syrian Kurdish fighters for this week's suicide car bomb attack in the Turkish capital that killed 28 people and fears the creation of a Kurdish stronghold along its southern border, although a Turkey-based offshoot of the Kurdish Worker's Party (PKK) has now claimed responsibility for the blast. 

Some 21 suspects held over the Ankara attack were due to appear in court on Sunday, local media reported.

"The situation we are currently facing is one of legitimate defence. No one can deny or limit Turkey's legitimate right to defence in the face of terrorist attacks," Erdogan said in a speech in Istanbul late on Saturday, according to the Dogan news agency.

Erdogan's remarks come after the United States, France and Russia all urged Turkey to scale back or halt its military action in Syria.

US President Barack Obama, in a phone call with Erdogan on Friday, urged the Ankara government and the Kurdish People's Protection Units (YPG) militia to "show reciprocal restraint" in northern Syria.

French President Francois Hollande also warned that Ankara's escalating involvement in the conflict was creating a risk of war between Turkey and Russia which back different sides in Syria's increasingly complex civil war.

Ankara insists that the Syria-based YPG is a branch of the outlawed PKK, which has waged a three-decade insurgency against the Turkish state and is recognised as a terror group by the United States and EU. While a peace deal between Ankara and the PKK was in the works last year, hostilities resumed in the summer after the Islamic State (IS) group killed 33 pro-Kurdish activists in the southern Turkish city of Suruc. 

Last week, Erdogan vowed not to allow the creation of a Kurdish stronghold in northern Syria, saying there was no question of stopping the artillery barrage.

"To fight the threats which it faces, Turkey has the right to launch any kind of operation in Syria and wherever else the terrorist organisations are located," Erdogan said.

Turkish Foreign Minister Mevlut Cavusoglu last week accused the United States of making conflicting statements about the Syrian Kurdish militia.

"My friend [Secretary of State John] Kerry said the YPG cannot be trusted," Cavusoglu told reporters. 

"When you look at some statements coming from America, conflicting and confused statements are still coming ... We were glad to hear from John Kerry yesterday that his views on the YPG have partly changed."

Washington supports the Syrian Kurdish Democratic Union Party (PYD) and its YPG militia as the best fighting force on the ground against Islamic State (IS) militants but is also a close Turkey ally, despite Ankara's fierce rejection of the Kurdish militias.