Syrian regime forces backed by allied forces recaptured the village of al Ais, south of the city of Aleppo, from opposition forces just hours after the opposition took control of the town on Monday, the Syrian Observatory for Human Rights (SOHR) said on Tuesday.
Syrian opposition captured the village and at least two hilltops from Syrian regime forces on Monday, the SOHR said.
The fighters, including some from the Al Qaeda-affiliated Nusra Front and the armed opposition group Jund al-Aqsa, took the village of al-Ais and at least two hilltops in the same area in southern Aleppo Province.
According to the SOHR there were many casualties from the battle but the exact number is unknown.
Capturing the village of al Ais on Monday was the first advance by the oposition group this year.
On February 27, the US and Russia reached an agreement for a cessation of hostilities in Syria. However, the DAESH terror group and the Nusra Front were not covered by the deal.
Foreign powers hope the pause in fighting could lead to peace talks to end the conflict. But the agreement, which has not been directly signed by the Syrian warring parties and is less binding than a formal ceasefire, is very fragile and each side has accused the other of breaking it.
A Syrian rebel group said it came under attack launched by the regime on Tuesday in Kabani hill located in the province of Latakia.
"There is a major attack in but they haven't advanced. It has been going on for more than three hours," Fadi Ahmad, spokesman for an opposition faction named First Coastal Division, told Reuters.