The opposition-run Syrian news agency Thiqa posted a video online Saturday purported to show a missile falling on Darat Izza, a town in northwestern Aleppo province.
The footage showed a huge explosion and large plume of smoke rising over the town.
Russian and government forces continued to bomb rebel positions in the western part of the Aleppo province, Syrian activists said.
According to the Syrian Civil Defense, at least three people were killed and 15 others were injured in the airstrike.
Meanwhile, a temporary Russian halt on airstrikes on rebel-held parts of Aleppo expired.
Although Russian and Syrian officials called for the evacuation, local reports say none of the area's estimated 275,000 residents left the territory.
The Britain-based Syrian Observatory for Human Rights said Saturday that at least 74 civilians, including 25 children, were killed in the 8-day offensive launched by Syrian opposition fighters against the western edge of the government-held part of Aleppo city.
The Syrian military said 80 people were killed in the first three days of the rebel offensive.
It was not immediately possible to reconcile the discrepancy in casualty figures.