Reuters reports that a Turkish F-16 shot down a Syrian Mig-23 Sunday 23 March.  The Syrian plane allegedly violated Turkish airspace.  The Mig-23 was one of a pair of planes attacking rebel positions in an effort by Assad’s troops to seize a border outpost.  The plane was downed by an air to air missile and the wreckage landed 1200m inside the Syrian border.  This is the same area where Turkey shot down a Syrian helicopter six months ago.

After Syria downed a Turkish F-4 in 2012, Turkey responded with relaxed rules of engagement that consider Syrian aircraft approaching the Turkish border to be treated as a legitimate targets.  Turkey says it warned the Syrian planes away from the border four times before the Syrian plane violated the border.