Casualties are increasing as Turkey presses on with its cross-border offensive on Kurdish-held areas of northern Syria.
At least 11 civilians have died and dozens of fighters from the Kurdish-led SDF and pro-Turkish factions have been killed, reports say.
The first death of a Turkish soldier was confirmed by Turkey's military.
Tens of thousands of people have fled their homes, amid growing international criticism of the offensive.
Turkey moved into northern Syria on Wednesday after the the US president, Donald Trump pulled American troops out of the area.
Analysts say the US withdrawal effectively gave Turkey the green light to begin its cross-border assault.
Republicans in the US House of Representatives on Tuesday announced plans to introduce a sanctions bill against Turkey
Turkey defended its offensive as a bid to create a "safe zone" free of Kurdish militias which could also house Syrian refugees.
Turkey regards the Kurdish militias of the Syrian Democratic Forces (SDF) – which have controlled the cross-border areas – as "terrorists" who support an anti-Turkish insurgency.
The SDF have been key allies of the US in the battle against the Islamic State (IS) group.
One major concern for the international community is the fate of thousands of suspected IS prisoners, including many foreign nationals, being guarded by Kurdish-led forces in the region.
What's the latest on the fighting?
On Thursday, Turkish troops partly encircled the border towns of Ras al-Ain and Tal Abyad.
The Kurdish Red Crescent said there had been 11 confirmed civilian deaths so far and 28 serious injuries, mostly in Ras al-Ain and another border town, Qamishli. Some are children.
At least five people, including a Syrian baby, were reportedly killed in Kurdish shelling of Turkish border towns.
Activists from the Syrian Observatory for Human Rights reported at least 29 deaths among the SDF and 17 from among pro-Turkish Syrian rebels, the Syrian National Army, as more than 10 villages fell into Turkish hands.
In a later report they said that seven members of the pro-Turkish forces had been killed as the SDF retook a village in Tal Abyad region, one of them a Turkish soldier.
Turkey's military confirmed a soldier's death, and said three others had been wounded.
Turkey's Anadolu news agency said late on Thursday that 228 Kurdish militants had been "neutralised" since the start of the operation.
Meanwhile a refugee crisis is developing. Some 64,000 people have already reportedly fled their homes, the International Rescue Committee aid organisation said.
Aid groups say as many as 450,000 could be forced to move.
Turkey wants to create a "safe zone" running for 480km (300 miles) along the Syrian side of the border but says it will not advance deeper than a planned 32km limit.
The groups on the ground
- SDF – Syrian Democratic Forces – A multi-ethnic alliance of mostly Kurdish and Arab militias that has been the critical partner on the ground in Syria for the US-led multinational coalition against the jihadist group Islamic State (IS).
- YPG – People's Protection Units – The military wing of the Syrian Kurdish Democratic Union Party (PYD). It is the dominant force in the SDF. The Women's Protection Units (YPJ) is the YPG's all-female brigade.
- PKK – Kurdistan Workers' Party – A Kurdish rebel group that has fought for Kurdish autonomy in Turkey for three decades. It is designated as a terrorist group by Turkey, the US and EU. Turkey says the YPG is an extension of the PKK – a claim both groups deny.
- SNA – Syrian National Army – The new name for a loose alliance of Syrian rebel factions backed by Turkey previously known as the Free Syrian Army (FSA). SNA fighters are taking part in the ground offensive in north-eastern Syria.
What has the reaction been?
The UN Security Council discussed the situation on Thursday at the request of its current five EU members – the UK, France, Germany, Belgium and Poland – who are calling for Turkey to halt its military offensive.
UN Secretary General Antonio Guterres expressed his "deep concern" at the rising violence.
On Friday Nato Secretary General Jens Stoltenberg said he had shared "serious concerns" about the operation in a meeting with Turkish Foreign Minister Mevlut Cavusoglu.
He expected Turkey, a Nato member, to "act with restraint", he added.
Mr Erdogan has strongly defended the incursion, threatening to send some ofRead More – Source