"We are at war", Erdoğan added. However, he said that the cause of the incident is still unclear.
Kurdish news sources said the the helicopter was shot down in Afrin's Rajo district.
The US-allied YPG and its left-wing political parent the Democratic Union Party (PYD) ruling Rojava say they are establishing a libertarian Communalistic system in line with the late obscure American political theorist Murray Bookchin whose writings have affected the thinking of PKK founder Abdullah Ocalan, jailed in Turkey. The campaign followed Ankara's promises to "strangle" the new Border Security Force (BSF) in Syria.
The U.N. High Commissioner for Human Rights Zeid Ra'ad Al Hussein called Saturday for urgent worldwide action, saying the past week in Syria "has been one of the bloodiest periods of the entire conflict". Seven Turkish civilians have also lost their lives. 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.
The Britain-based Syrian Observatory for Human Rights said 30 people were wounded by air strikes and artillery fire but that the intensity of the bombardment targeting the Eastern Ghouta region near the capital had lessened from Friday night.
Winter Olympics: Games organisers confirm cyber attack, won't reveal source
But PyeongChang was ahead of the Summer Olympics two years ago, when the Rio Opening Ceremony produced a 16.5 rating . The rhetoric war between North Korea and the Trump administration hasn't skipped a beat in PyeongChang .
"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". Syrian ally Russian Federation has cast 11 vetoes on possible Security Council action on Syria since the civil war began in 2011, shielding Syrian President Bashar al-Assad's government.
Syrian President Bashar al-Assad's assault on the rebel-held region of Eastern Ghouta has continued despite worldwide pleas for a ceasefire.
The draft United Nations resolution, seen by Reuters, also "calls upon all parties to immediately lift the sieges of populated areas, including in Eastern Ghouta, Yarmouk, Foua and Kefraya".
The Council is expected to begin debate on the resolution Monday.