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". Mr Erdogan warns of civil war in Syria.

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.

July 20, 2015 At least 32 people die when a suspected Isil suicide bomber attacks a gathering of activists in the town of Suruc, near the Syrian/Turkish border.

July 22, 2015 The Kurdistan Workers' Party (PKK) claims the killing of two Turkish policemen in the border town of Ceylanpinar in revenge for the Suruc massacre.A government spokesman denounces the murders as "a terrorist act perpetrated by a terrorist organisation."

July 23, 2015 Jihadists inside Syria open fire on a Turkish army border post in the Kilis region, killing a non-commissioned officer and wounding two soldiers. In Diyarbakir, a majority Kurdish city in south-eastern Turkey, gunmen kill a Turkish policeman and seriously wound another.

July 24, 2015 Turkish F-16 jets hit Isil targets just inside Syria for the first time, killing nine Isil militants. Late in the day, airstrikes also target PKK militants in northern Iraq.

July 25, 2015 Turkish air strikes intensify against Isil jihadists in Syria and PKK militants in Iraq.

July 26, 2015 Ankara launches F-16 attacks for the third day, striking Kurdish command posts in northern Iraq. Turkish protesters battle security forces in Istanbul, a policeman is shot and killed. Turkey asks for an extraordinary Nato meeting to discuss its cross-border offensive, but has not asked for help, the group's chief says.