Turkey has shelled Islamic State positions in Syria for a second day, as expectations grow of a major Ankara-backed offensive against the jihadis.
With tensions high on the Turkey-Syria border after the bombing of a wedding in the Turkish city of Gaziantep killed 54 people, howitzers hit Isis and Kurdish rebel targets across the frontier on Monday.
In fighting on Tuesday, two mortar rounds fired from an Isis-controlled area in Syria hit the south-eastern Turkish town of Karkamış, Turkish television reported. Turkish artillery responded by firing about 60 shells on four positions around the Isis-controlled Syrian town of Jarablus, it said.
Turkey has had one of the bloodiest years in its modern history, facing a string of attacks by Isis and Kurdish militants and an attempted coup on 15 July.
The shelling came as Syrian activists said hundreds of Turkish-backed Syrian opposition fighters had gathered in the border area of Karkamış to prepare for an offensive to seize control of Jarablus.
This could potentially put them on a collision course with the militia of the Kurdish Democratic Union party (PYD), which Ankara vehemently opposes. The PYD has its eyes on Jarablus after seizing the strategic Manbij area in northern Syria from Isis.
Rami Abdul Rahman, the head of the Syrian Observatory for Human Rights, said the Turkish shelling in Syria aimed to prevent the advance of troops backed by Kurds towards Jarablus.