Some 1,500 Turkish-backed Syrian rebels are thought to be in the Turkish town of Gaziantep waiting to attack.
The Turkish artillery fire followed a massive suicide bombing in Gaziantep. A bomber suspected of links with the IS killed 54 people, including 22 children, at a Kurdish wedding, in the deadliest attack in Turkey this year.
As many as 66 people are still in hospital, out of which 14 are in a serious condition.
President Tayyip Erdogan said on Sunday that the attack was carried out by a suicide bomber aged between 12 and 14, adding that initial evidence pointed to the IS.
But Prime Minister Binali Yildirim on Monday said it was too early to verify the organisation responsible or whether the attack was carried out by a child.
The wave of bombings in Turkey could intensify as the country becomes ever more embroiled in the Syrian war, the media reported.
A coalition including Syrian Kurdish YPG forces has been pushing the IS out of Syrian towns, including Manbij.
However, the Turkish bombardment has also struck YPG positions north of Manbij.
Turkey views the YPG as an extension of the Kurdistan Workers Party (PKK), a Turkish-Kurdish rebel group fighting for autonomy within Turkey since the 1980s.