Turkish Prime Minister Recep Tayyip Erdogan says the country's military shot down a Syrian fighter jet that flew into Turkish airspace on March 23.
Erdogan warned Syrian President Bashar al-Assad's regime of a "heavy response" for airspace violations.
Damascus confirmed one of its warplanes was shot down while pursuing rebels in Syrian territory near the border.
It accused Turkey of "flagrant aggression."
Syrian opposition activists say the plane was flying near a border crossing captured on March 21 by Syrian rebels.
The British–based Syrian Observatory for Human Rights reported "heavy fighting" on March 23 near the crossing, close to Kasab -- a town in Syria’s northwestern Latakia Province with a large ethnic Armenian community.
Syrian state television says government forces inflicted "heavy losses" on rebels there who "entered Syria from Turkey."
Based on reporting by Reuters, AP, AFP, and NTV