Seven soldiers have been killed when a Turkish military helicopter crashed in northern Syria in Ankara’s offensive on Syrian Kurdish militia.

Turkey’s president Recep Tayyip Erdogan announced that the helicopter was “downed” in the Afrin operation.

President Erdogan did not mention by name the Syrian Kurdish People’s Protection Units, or YPG, but hinted they were to blame.

However, the country’s prime minister said soon after that the cause of the crash was not yet clear and investigations were ongoing.

“We don’t have exact evidence or document to determine that it went down with any outside interference,” said Binali Yildirim.

The Turkish military said two soldiers were killed when its attack helicopter crashed and was destroyed. A technical team launched an investigation.

A spokesman for the Kurdish militia, Mustafa Bali, said his fighters brought down the aircraft in Raju, north-west Afrin.

In a video posted online by the YPG-dominated Syrian Democratic Forces, a helicopter is seen flying over a tree-lined hill and another helicopter is captured during its crash. A helicopter is seen firing two rockets in the area as plumes of smoke from the crash rise over the trees.

Turkey launched a military offensive on January 20 to oust the YPG from Afrin, citing national security.

Turkey considers the YPG a terrorist organisation and an extension of an insurgency within its own borders that has fought for Kurdish autonomy for more than three decades.

President Erdogan arrives to address the party members in Istanbul( Murat Cetinmuhurdar/Pool Photo via AP )
President Erdogan arrives to address the party members in Istanbul (Murat Cetinmuhurdar/Pool Photo via AP )

The helicopter is the first aircraft Turkey has announced it has lost since the offensive began. The Turkish president said: “We might lose a helicopter but they’ll pay the price for this.”

In two other statements, the army announced five more Turkish soldiers were killed and nine wounded on Saturday, bringing the military death toll to 26 since January 20.

Syria has been gripped by a new and escalating round of violence in recent weeks.

Aside from the Turkish offensive in Afrin, the Syrian government has escalated its attacks on two of the largest and most important remaining opposition-held areas, in Idlib province in northwestern Syria and on eastern Ghouta, a region near the capital Damascus.

The violence has left hundreds killed and wounded as the Syrian government and its allies sought to consolidate their hold on remaining opposition-controlled areas.

The UN High Commissioner for Human Rights Zeid Ra’ad Al Hussein has called for urgent international action, saying the past week in Syria “has been one of the bloodiest periods of the entire conflict.”

The commissioner said the “no-holds-barred nature” of the assault included attacks on nine medical facilities and the death of 277 civilians between February 4 and February 9 in both Idlib and eastern Ghouta.

There were also reports of the government using toxic agents in residential areas.

In eastern Ghouta, nearly 400,000 residents are trapped by a tightening government siege and the violence. At least two million people live in Idlib, the largest area controlled by the opposition.

“Even by Syria’s atrocious standards, these are exceptionally deplorable developments – and a cruel irony given that both have been declared ‘de-escalation areas’,” said Mr Al Hussein.

Both Idlib and eastern Ghouta are part of Russia-negotiated de-escalation areas, which are meant to freeze the lines of conflict and allow in humanitarian aid.

Mr Al Hussein said the prevailing climate of impunity and the paralysis of the UN Security Council, divided between allies and foes of the Syrian government, calls for the Syrian conflict to be referred to the International Criminal Court, and a more concerted effort by the parties involved to bring about peace.

“The conduct and management of this war has been utterly shameful from the outset, and the failure to end it marks an epic failure of global diplomacy,” said Mr Al Hussein.