International peace envoy Lakhdar Brahimi arrived in Istanbul Saturday to discuss the growing tension between Turkey and neighboring Syria over cargo seized from a Syrian passenger plane.

Turkey intercepted a Syrian plane Wednesday en route from Moscow to Damascus. Turkey has defended its decision to intercept the plane, saying the aircraft was carrying military equipment and ammunition destined for Syria's government.

Syrian officials deny the plane was carrying any military cargo.

Russia, a top ally of Syrian leader Bashar al-Assad, has demanded an explanation from Turkey, saying its actions threatened the lives and safety of the passengers on board.

Brahimi spoke with Saudi King Abdullah about the crisis Friday. Meeting in Jeddah, the two agreed on the need to stop the bloodshed and aid the millions of Syrians affected by the violence in the country.

On Friday, Syrian rebels clashed with government troops over control of an air defense base near Aleppo, the country's most populous city.

Activists say rebels attacked the air force post outside Aleppo, but there are conflicting reports as to whether the rebels have taken over the base.

Fighting also continued in several other Syrian locales.