Turkey is being dragged further into the four-year conflict in neighbouring Syria following a deadly suicide attack, blamed on Isil, that killed 32 activists near the border.

September 13, 2011 "The Syrian people do not believe al-Assad, I do not either," says Recep Tayyip Erdogan, then premier, a few months after calling the Syrian leader his "friend". Erdogan warns of civil war in Syria. "I fear that matters will end with a civil war breaking out between the Alawites and the Sunnis," he says in reference to Assad's Shia Alawite sect, and the majority Sunni Muslims.

October 2, 2011 Following a series of meetings in several Turkish cities, Syrian opposition leaders announce the creation of the Syrian National Council (SNC), which groups political factions opposed to the Assad regime.

November 15, 2011 Turkey passes its first sanctions against Syria, and halts joint oil exploration with the country.

June 22, 2012 A Turkish plane that Ankara says was on a training mission in international airspace is shot down by Syrian forces.

May 11, 2013 Twin attacks kill 52 people in Reyhanli, a large Turkish town near the border with Syria.

September 16, 2014 Isil militants attack the Syrian border town of Kobane, and seize parts of it. Kobane becomes the scene of fierce battles.

May 16, 2015 Turkey says it has shot down a Syrian helicopter that violated its airspace.