At least two people have died in the Turkish border town of Kilis after rocket fire hit a mosque.
It's the latest in a series of such attacks since the start of Turkey's military operation in Syria's Afrin region aimed at 'eliminating' Kurdish YPG militia.
Ankara's air and ground mission has now entered its sixth day.
Turkish troops have been meeting stiff resistance from the Kurdish forces who are backed by the US as they take on so-called Islamic State in Syria.
Concern in Washington over the military operation produced a phone call from US President Donald Trump.
In a transcript it says Trump urged his Turkish counterpart Recep Tayyip Erdogan to "deescalate, to limit his military's actions, and to avoid civilian casualties.
It's unclear how many people have died in "Operation Olive Branch" . A monitoring service says at least 27 civilians have been killed.
Turkey says its operation will continue until the YPG who it accuses of having links with its own Kurdish insurgents have been crushed.