Al-Qaeda's Syria affiliate and allied jihadists on Monday seized a set of strategic hilltops held by pro-regime forces in the country's north, a monitoring group said, according to AFP.
The Syrian Observatory for Human Rights said the jihadist rebels battled government loyalists and overran three hilltops in the Al-Eis area south of Aleppo city.
"Fighters from Al-Nusra Front, Jund Al-Aqsa, and other groups seized the central Al-Eis hilltop and surrounding hills as well," Observatory head Rami Abdel Rahman told AFP.
The jihadists detonated five car bombs during their offensive, he added.
"The hilltops are important because they reinforce the regime's presence in the outskirts of Aleppo and gave them a presence near the main highway south towards Damascus," Abdel Rahman explained.
Aleppo province is broken up into a complex patchwork of territories under the control of various groups.
The Islamic State (ISIS) group is dominant in the east, while rebel groups – some allied with Al-Nusra – control much of the west.
Government forces based south of Aleppo city have tried to expand their control north and east.
Monday was the tenth day of a landmark ceasefire across parts of the country brokered by the United States and Russia.
The truce, however, does not include areas held by ISIS and Al-Nusra. In fact, the head of Al-Nusra Front has urged opponents of President Bashar Al-Assad to reject the ceasefire and instead intensify attacks on the regime.
More than 270,000 people have been killed in Syria since the conflict began in March 2011, evolving from widespread anti-government protests to a brutal war.
AFP contributed to this report.