Turkey has bombarded Islamic State in northern Syria for a second day after its foreign minister promised to "cleanse" the border.

Its military hit four IS positions in Jarabulus with around 60 shells early this morning after firing on IS and Democratic Union Party (PYD) Kurdish militia targets on Monday evening.

It is thought Turkish-backed Syrian rebels are preparing to launch an attack to seize the border town from Islamic State.

Turkish media are reporting the latest artillery exchanges are in response to mortar fire from across the border. 

Two mortar rounds reportedly hit the southeastern Turkish town of Karkamis, which neighbours Jarabulus, but there are no reports of casualties.

Security forces subsequently sealed off the area and warned people over loudspeaker to stay at home.

Turkey's foreign affairs minister, Mevlut Cavusoglu, yesterday said Islamic State must be totally cleansed from northern Syria.

"Daesh [IS] should be completely cleansed from our borders and we are ready to do what it takes for that," he said.

It comes after this weekend's suicide bombing at a wedding in the city of Gaziantep - close to the Syrian border - killed 54 people.

Dozens of others were injured in the explosion and a government official said at least 22 of the victims were under 14 years old. 

Turkish authorities initially blamed the blast on a child bomber linked to IS, believing it was retaliation for offensives by Kurdish militias and pro-Ankara Syrian opposition forces fighting IS in Syria.

But Prime Minister Binali Yildirim has said early information was wrong and they "do not have a clue" who carried out the attack.

Turkey regards the Kurdish PYD political party as a terror group, although Washington sees the Kurdish militias as having an important role in the fight against IS.

America's Vice President Joe Biden is scheduled to visit Ankara for talks tomorrow.