Turkey has stepped up its air and artillery strikes on Kurdish militia in northeast Syria, escalating an offensive that has drawn warnings of humanitarian catastrophe.
The incursion, launched after US President Donald Trump withdrew US troops who had been fighting alongside Kurdish forces against Islamic State militants, has opened a new front in the eight-year-old Syrian civil war and drawn fierce international criticism.
In Washington, Trump - fending off accusations that he abandoned the Kurds, loyal allies of the United States - suggested that Washington could mediate in the conflict, while also raising the possibility of imposing sanctions on Turkey.
On Friday, Turkish warplanes and artillery struck around Syria's Ras al Ain, one of two border towns that have been the focus of the offensive. Reuters journalists heard gunfire there from across the frontier in the Turkish town of Ceylanpinar.
A convoy of 20 armoured vehicles carrying Turkish-allied Syrian rebels entered Syria from Ceylanpinar. Some made victory signs, shouting "Allahu akbar" (God is greatest) and waving Syrian rebel flags as they advanced towards Ras al Ain.
Some 120km to the west, Turkish howitzers resumed shelling near the Syrian town of Tel Abyad, a witness said.
Overnight, clashes erupted at different points along the border from Ain Diwar at the Iraqi frontier to Kobani, more than 400km to the west. Turkish and SDF forces exchanged shelling in Qamishli among other places, the SDF's Qamishlo said.
Turkish forces have seized nine villages near Ras al Ain and Tel Abyad, said Rami Abdulrahman, director of the Syrian Observatory for Human Rights, which monitors the war.
At least 32 fighters with the SDF and 34 Turkey-backed Syrian rebels have been killed in fighting, while 10 civilians have been killed, Abdulrahman said. The SDF said 22 of its fighters were killed on Wednesday and Thursday.
Turkey says it has killed hundreds of SDF fighters in the operation and one Turkish soldier has been killed.
In Syria's al Bab, some 150km west of the offensive, about 500 Turkish-backed Syrian fighters were set to head to Turkey to join the operation, CNN Turk reported.
It broadcast video of them performing Muslim prayers in military fatigues, their rifles laid down in front of them, before departing for Turkey.
Turkey says the purpose of its assault is to defeat the Kurdish YPG militia, which it sees as an enemy for its links to insurgents in Turkey. It says it aims to set up a "safe zone" inside Syria, where it can resettle many of the 3.6 million refugees it has been hosting.
The International Rescue Committee aid group says 64,000 people in Syria have fled in the first days of the campaign.
The Kurdish YPG is the main fighting element of the Syrian Democratic Forces (SDF) which have acted as the principal allies of the United States in a campaign that recaptured territory held by the Islamic State group.
A camp sheltering more than 7000 displaced people in northern Syria is to be evacuated and there are talks on moving a second camp for 13,000 people including Islamic State fighters' familes, after both were shelled, Kurdish-led authorities said.
Medecins Sans Frontieres said a hospital in Tel Abyad had been forced to shut after most of its staff fled from bombings over the past 24 hours.
NATO Secretary General Jens Stoltenberg said after talks with Foreign Minister Mevlut Cavusoglu in Istanbul that he expected Turkey to act with restraint in Syria. Cavusoglu said Ankara expected "strong solidarity" from the alliance.
Russian President Vladimir Putin warned that Islamic State militants could escape from jail as a result of the Turkish offensive, the Interfax news agency reported.
© RAW 2019