Turkish war planes carried out air strikes on Kurdish militant bases in northern Syria and northern Iraq on Sunday, destroying 89 targets, Turkey's defence ministry said, in retaliation for a bomb attack in Istanbul that killed six people one week ago, Reuters reports.
The strikes targeted bases of the outlawed Kurdistan Workers Party (PKK) and the Syrian Kurdish YPG militia, which Turkey says is a wing of the PKK, the ministry added in a statement.
Ankara has blamed Kurdish militants for the blast on Istanbul's Istiklal Avenue on Nov. 13 that killed six people and injured more than 80. No group has claimed responsibility for on the busy pedestrian avenue, and the PKK and Kurdish-led Syrian Democratic Forces (SDF) have denied involvement.
The strikes were carried out in Qandil, Asos and Hakurk in Iraq and Kobani, Tal Rifat, Cizire and Derik in Syria, the ministry said.
The 89 targets destroyed included shelters, tunnels and ammunition depots, it said, adding that "so-called directors of the terrorist organisation were among those neutralised".
A spokesman for the SDF said that the Turkish strikes had destroyed infrastructure including grain silos, a power station and a hospital. Eleven civilians, including a journalist, died, said Farhad Shami, head of the SDF media centre on Twitter.
The SDF said in a statement they would retaliate for the strikes. "These attacks by the Turkish occupied forces will not go without a response," it said.
Separately, a Syrian military source told state media SANA that a number of servicemen had been killed in "Turkish aggression on Syrian land" on Sunday morning, in the countryside near northern Aleppo and Hasaka.
Turkey's Defence Minister Hulusi Akar said in a statement that all necessary measures were taken to avoid damage to innocent people and the surroundings, adding that "only and only terrorists and structures belonging to terrorists were targeted."
"The claw of our Turkish Armed Forces was once again on top of terrorists," he added, dubbing the operation "Claw Sword."
A Turkish official said on Tuesday Ankara plans to pursue targets in northern Syria after it completes a cross-border operation against the PKK militants in Iraq.
"It is time to give account for Istiklal," Turkish presidential spokesman Ibrahim Kalin wrote on Twitter on Sunday.
Turkey has conducted three incursions so far into northern Syria against the YPG militia. President Tayyip Erdogan has previously said Turkey could conduct another operation against the YPG. Ankara has also escalated drone strikes in Syria in recent months, killing a number of key SDF officials.
Ankara regularly carries out air strikes in northern Iraq and has sent commandos to support its offensives as part of a long-running campaign against the PKK in Iraq.
The PKK has led an insurgency against the Turkish state since 1984. It is considered a terrorist organisation by Turkey, the United States and the European Union.
Washington has allied with the YPG in the fight against Islamic State in Syria, causing a rift with NATO ally Turkey.