Turkish President Recep Tayyip Erdogan has signalled a possible ground offensive in northern Syria and Iraq after Ankara’s forces launched cross-border air raids on what they said were locations used by Kurdish groups they blame for a bombing in central Istanbul, writes Al Jazeera.

The escalating tensions have prompted global concern, with Russia and the United States urging Ankara on Monday to show restraint.

Speaking to reporters on a flight home from Qatar after attending the opening of the World Cup, Erdogan said Turkey’s ongoing military campaign in northern Syria and northern Iraq “is not limited to just an air operation” and could involve ground forces.

“Competent authorities, our defence ministry and chief of staff will together decide the level of force that should be used by our ground forces,” he said. “We make our consultations and then we take our steps accordingly”.

The Turkish operation – dubbed Claw Sword – was launched on Sunday, a week after a bomb blast on Istanbul’s Istiklal Avenue killed six people and wounded 81.