ISIL also lost 15 militants in the attack, the monitor said.
At least two more civilians were injured in Isis shelling in the nearby town of Salamiyeh.
IS was now fully in control of Aqareb, SOHR said, adding that the government had sent reinforcements to the area.
The villages are north of al-Salamiya close to the only road still useable between Aleppo and other parts of Syria held by the government.
While there are reports several government positions were captured and fighting is still ongoing, Syrian state television said that the regime gunmen managed to repel the attack and launched a counteroffensive in the form of air strikes.
Some of the bodies were badly mutilated, beheaded or had their limbs severed but 'most appear to have died as a result of gunfire, ' Safar told The Associated Press by telephone.
IS previously attacked Al-Mabujeh in March 2015, killing more than 37 residents.
He said at least nine children were beaten on the head with heavy objects such as bricks or stones.
Fierce clashes between IS fighters and pro-Syrian government forces in the villages of Aqareb and Al-Mabujeh left at least 15 civilians and 27 pro-regime troops dead, according to the Syrian Observatory for Human Rights, which has monitors in the area. He said IS deployed snipers on roofs of some buildings in Aqareb al-Safi.
The militants broke into villagers' houses at dawn, the government-run SANA news agency said.
A dozen people were also wounded by the artillery fire, which hit a wedding party.
Moscow joined in the condemnation calling the strike on Syrian forces "unacceptable", state media reported, after the bombing of pro-government troops.
Al-Fayad convoyed an oral message from al-Abadi to President al-Assad, in which he asserted the importance of continuing to strengthen the existing cooperation between Syria and Iraq in their war against the Takfiri terrorist organizations, especially with regard to coordination of efforts in combating ISIS terrorist organization on the shared border line between the two countries.
The Sunni extremist group has slaughtered thousands of Shia and other opponents in Syria and Iraq, often boasting about the killings and circulating photos and videos of them online.