Turkey has struck Kurdish militant bases in retaliation for a bomb attack in Istanbul last week.
The air strikes on the bases in northern Syria and northern Iraq killed 11 civilians, including a journalist, the Kurdish-led Syrian Democratic Forces (SDF) said.
Six people were killed in the bombing in central Istanbul. The SDF has denied any involvement.
The strikes today destroyed 89 targets, the Turkish ministry of defence said.
Hulusi Akar, the defence minister, insisted that “only terrorists and structures belonging to terrorists were targeted” in Operation “Claw Sword” and said all necessary measures were taken to avoid civilians.
He added: “The claw of our Turkish armed forces was once again on top of terrorists.”
The ministry said the strikes had targeted bases of the banned Kurdistan Workers Party (PKK) and the Syrian Kurdish YPG militia.
Turkey considers the PKK a terrorist group and says the YPG, which forms the backbone of the SDF, is a wing of the PKK.
Shelters, tunnels and ammunition depots in Qandil, Asos and Hakurk in Iraq and Kobani, Tal Rifat, Cizire and Derik in Syria were destroyed, the ministry said.
The SDF, which said it would retaliate for the strikes, said the attacks had destroyed infrastructure including grain silos, a power station and a hospital.
Farhad Shami, head of the SDF media centre, wrote on Twitter that 11 civilians, including a journalist, had been killed.
No group has so far claimed responsibility for the attack in Istanbul last Sunday, which injured 80 people.
The PKK has said it would not “directly target civilians” and denied responsibility.
Earlier in the week a Turkish official said Ankara planned to pursue targets in northern Syria after it completed a cross-border operation against PKK militants in Iraq.
Turkey has conducted three incursions so far into northern Syria against the YPG militia, with President Tayyip Erdogan previously saying Turkey could conduct another operation against them.
Ankara has also escalated drone strikes in Syria in recent months, killing a number of key SDF officials.
They regularly carry out air strikes in northern Iraq.
The PKK – which the EU and US also consider a terrorist organisation – has led an insurgency against the Turkish state since 1984.
Their aim is to establish an independent Kurdish stage in the southeast of the country.
The US allied with the YPG in the fight against Islamic State in Syria, causing a rift with NATO ally Turkey.