The Syrian army and its allies have made further advances in a major offensive that could cut insurgents' supply lines between the northwestern city of Aleppo and the Turkish border, according to the Syrian Observatory for Human Rights.
Tuesday's advances, which were also reported by Syrian state media, were backed by allied militia and heavy Russian air support.
They appear to be aimed at breaking through rebel-held territory north of Aleppo to reach the Shi'ite villages of Nubul and al-Zahraa.
They are loyal to Damascus and surrounded by opposition groups.
It is the first major offensive north of Aleppo - a city split into areas held by the government and the opposition - since Russia began its air campaign in support of President Bashar al-Assad on September 30.
Damascus and its allies have pressed ahead with a number of offensives in western Syria even as the United Nations tries to advance peace talks in Geneva, recently seizing important towns in the northwest and southwest.
On Monday they seized the strategic village of Hardatnin, about 10km northwest of Aleppo, the Observatory said.
The army and allied combatants gained ground in coastal areas last month and have also launched a large-scale assault in southern Syria against insurgents.