Observatory head Rami Abdel Rahman said "military aircraft" had targeted the market in Maaret al-Numan, blaming the regime for the strike.
On Saturday, the USA said it backed Turkish plans to intervene in northern Syria.
Sofge said some 2,000 IS fighters were still in the area.
The illegitimate referendum saw Iraqis in KRG-controlled areas - and in a handful of territories disputed between Erbil and Baghdad, including ethnically mixed Kirkuk and Mosul - vote on whether or not to declare independence.
Erdogan told reporters after the meeting that Russian Federation supports the operation from the air while supported by Turkish soldiers from within the Turkish border.
He pointed out to the presence of serious action now taking place in Idlib to achieve security.
The Turkish president made the remarks at the 26th semi-annual consultation and assessment meeting of his ruling Justice and Development Party (AKP) in Turkey's western city of Afyonkarahisar on Saturday, describing the operation as being "serious".
Idlib and surrounding areas of northwest Syria are among the largest bastions for rebel groups fighting Syrian President Bashar al-Assad, but have increasingly fallen under the sway of jihadist insurgent factions.
The province is one of four such de-escalation zones agreed upon across Syria.
"We will absolutely not allow the creation of a terror corridor along our borders", said Erdogan.
Several mortar shells landed near the Bab al-Hawa border crossing between Syria and Turkey, believed to be fired from the Turkish side of the border.
The FSA groups supported by Turkey are now ready to enter Idlib, Mustafa Sejari, a senior official in the Liwa al-Mutasem group said.
Entering Idlib by the Turkish-backed rebels and possibly Turkish forces comes in the context of the de-escalation zone deal, which was concluded between Russian Federation and Turkey in the recent sixth round of Astana talks on Syria. The fight in Abu Dali comes amid reports of an imminent Turkish-backed operation in northwestern Idlib province against the militants.
Syrian rebels backed by Turkish troops make up the Euphrates Shield military alliance, which controls parts of northern Syria an offensive against Kurdish and Islamic State group forces.
"When you enter a boxing match, you don't count how many punches you will throw", Erdogan said.