ANKARA/BEIRUT (Reuters) - Turkey fired into Kurdish-controlled northwestern Syria on Wednesday after saying one of its soldiers was killed by a sniper shot from across the border, highlighting its deepening tensions with a Kurdish militia backed by the United States.
The Turkish military said the soldier was killed in the Turkish province of Hatay, across the border from Syria's Afrin, which is controlled by the Kurdish YPG militia.
The YPG is a military ally of the United States and is playing a major part in U.S.-backed operations against Islamic State in areas of Syria further to the east.
It has also built ties to Russia, and said this week that Moscow was setting up a military base in Afrin and would help train its fighters.
Turkey, which is a NATO member and part of the U.S.-led coalition against Islamic State, views the YPG as a terrorist organisation, an arm of the Kurdistan Workers Party (PKK) militant group pressing an insurrection in Turkey.
It has been incensed by U.S. support for the YPG and has warned it will not tolerate a "terror state" being established in northern Syria. It accuses the YPG of rights abuses and of trying to displace Syrian Arab and Turkmen civilians.
YPG spokesman Redur Xelil said that the Turkish army was the aggressor in Wednesday's incident and that Turkish shelling of border villages around Afrin had wounded 10 civilians and was still continuing.
"We will certainly not stand with our hands tied in the face of any aggression and we will use the right to respond in the framework of legitimate self defence," he told Reuters in a written message.
To Turkey's dismay, Syrian Kurds have managed to bring both Washington and Moscow onto their side after showing themselves as an organised force able to confront jihadist groups and take back territory from Islamic State.
The Russian defence ministry said on Monday it had no plans to open new military bases in Syria but that a branch of its "reconciliation centre", which negotiates local truces in Syria, had been located in Aleppo province near Afrin.
The YPG said Russian troops had already arrived in Afrin with troop carriers and armoured vehicles.
Reporting by Tulay Karadeniz and Tom Perry; Writing by Tuvan Gumrukcu; Editing by Nick Tattersall