Turkiye announced early Sunday it had carried out air strikes against outlawed Kurdish militant bases across northern Syria and Iraq which it said were being used to launch “terrorist” attacks on its soil.

The offensive codenamed Operation Claw-Sword comes after a deadly blast in central Istanbul last Sunday which killed six people and wounded 81, with Turkiye blaming a banned Kurdish group.

“We are starting Operation Claw-Sword from now on,” Defense Minister Hulusi Akar said at the air force operations center before the planes left their bases to hit the targets in northern Iraq and Syria.

The raids targeted bases of the outlawed Kurdistan Workers’ Party (PKK) and the Kurdish People’s Protection Units (YPG), which Ankara considers an extension of the PKK, the defense ministry said.

“In line with our self-defense rights arising from Article 51 of the United Nations Charter, air operation Claw-Sword was carried out in the regions in the north of Iraq and Syria which are used as bases for attacks on our country by terrorists,” it added.

Turkiye blamed the PKK for the Istanbul bombing, the deadliest in five years and which evoked bitter memories of a wave of nationwide bombings from 2015 to 2017 that were attributed mostly to Kurdish militants and Daesh group jihadists.