ISTANBUL (REUTERS) - Turkish warplanes carried out air strikes against Kurdistan Workers Party (PKK) targets in northern Iraq late on Sunday (Dec 11), destroying a headquarters of the militants and surrounding gun positions and shelters, Turkey's military said.

The strikes, which a statement said targeted Iraq's Zap region, came hours after a PKK offshoot claimed responsibility for Saturday night's twin bombings that killed 38 people and wounded 155 outside an Istanbul soccer stadium.

PKK militants, who have fought a three-decade insurgency in Turkey's largely Kurdish southeast, are based in northern Iraq's mountains and have been regularly targeted by Turkish warplanes since a two-year ceasefire collapsed in July last year.

More than 40,000 people have been killed in the conflict, including several thousand since the fighting resumed last year, returning to levels not seen since the 1990s.

Turkey, the United States and the European Union designate the PKK as a terrorist organisation.