Syrian rebels have clashed with government troops over control of an air defense base near the country's most populous city.
Activists say rebels attacked the air force post Friday outside Aleppo, but there are conflicting reports as to whether the rebels have taken over the base.
Fighting continued in several Syrian locales. The opposition Syrian Observatory for Human rights said that six rebels were killed in an attack on a military checkpoint in Dara'a province that left 14 soldiers dead.
The group says air bombardments and heavy clashes are taking place in Idlib, Deir Ezzor and Aleppo provinces.
The activists say 260 Syrians were killed in fighting Thursday, including 86 civilians, 60 rebel fighters, 13 defected soldiers, and 92 regime forces. There was no government comment on the reports and Syria does not permit journalists to report freely in the country.
Video from inside Aleppo posted on the internet showed friends and family members mourning loved ones as residents continued to flee from shelling. A doctor at a local hospital said his facility treats ten to 15 injured children each day, and many often end up dying from their wounds.
The latest violence comes after Turkey defended its decision to intercept a Syrian-bound plane that it says was carrying military equipment and ammunition destined for Syria's government.
Turkish Prime Minister Recep Tayyip Erdogan said Thursday the Syrian-bound passenger jet, travelling from Moscow to Damascus earlier this week, was carrying illicit cargo provided by a Russian supplier. Mr. Erdogan did not elaborate on where Turkey received the intelligence or who in Russia had provided the materials.
Syrian officials have denied the plane was carrying any military cargo. Russia, a top ally of Syrian leader Bashar al-Assad, demanded an explanation from Turkey, saying its actions threatened the lives and safety of the passengers on board.
The Syrian Air flight was intercepted by fighter jets late Wednesday in the Turkish capital, Ankara. The plane was allowed to complete its trip to Syria early Thursday without the cargo.
The incident has increased tensions between Turkey and Syria, countries that in recent weeks have exchanged artillery fire across their shared border.