BBC News with Jonathan Izard. _______________________________________The Turkish General Staff said in a statement that the second Syrian plane heeded the warnings and turned back. Prime Minister Recep Tayyip Erdogan had earlier said Ankara would react forcefully to what he called any further incursions. James Reynolds reports. "Recep Tayyip Erdogan told a rally in Istanbul that Turkish F-16s hit a Syrian warplane after it violated Turkish airspace. If you violate our airspace, our slap after this will be hard, Mr. Erdogan told his supporters. One report from Damascus says that Syria condemns Turkish action as a flagrant act of aggression. The governments of Turkey and Syria have been on opposite sides of Syria's war since October 2011. Over the last year and a half, there have been a number of incidents along their 900km long border."