At least 54 people were reported killed and dozens wounded when an air strike hit a fuel station in Syria's northern province of al-Raqqa.
The Syrian Observatory for Human Rights cited an activist in the region saying that more than 110 people were among the dead and wounded.
Meanwhile, a Syrian military helicopter that crashed near the capital Damascus hit the tail of a passenger plane.
Syria's information ministry said the 200 people on board the plane were unharmed.
State news channel Suriya said earlier that a helicopter had crashed in the town of Douma east of the capital.
An activist in Damascus said rebels had shot down the helicopter but no rebel group has claimed the attack.
Rebel fighters seeking to overthrow President Bashar al-Assad have often fired at planes and helicopters used by the Syrian military to bombard opposition strongholds.
A helicopter was brought down on the outskirts of Damascus on 27 August.
Three days later, fighters in the northern province of Idlib said they had shot down a fighter plane near the Turkish border.
Rebels short of anti-aircraft capability have also launched ground attacks on airforce bases in the north and east of Syria to try to counter the military's air power.
