One of the most serious of these occurred on 3 October 2012, when an artillery shell fired from Syria by the Syrian Army killed five and injured at least ten Turkish citizens in the border town of Akçakale in Şanlıurfa Province, Turkey.

In June through July 2011, Turkey began sheltering the Free Syrian Army, offering the group a safe zone and a base of operation.

[11] Syria stated that it had shot the fighter down using anti-aircraft artillery near the village of Om al-Tuyour, while it was flying over Syrian territorial waters one kilometre away from land.

[17] As the clashes between the government forces and the opposition in Syria intensified, artillery shells began to fall across the border onto Turkish soil.

[22] On 4 October 2012, the Turkish parliament, the Grand National Assembly of Turkey passed a motion by a vote of 320-129 authorizing the use of military ground troops to enter "foreign countries" for operations.

[23][24] On 5 October 2012, shells fired by Syrian artillery in Latakia landed in the rural area of Aşağıpulluyazı village (Coordinates: 35°51′32.54″N 36°09′13.23″E / 35.8590389°N 36.1536750°E / 35.8590389; 36.1536750) in the Yayladağı district of Hatay Province.

The day before, Turkish Prime Minister Recep Tayyip Erdoğan had announced at a press conference during the official visit of Iranian First Vice President Mohammad-Reza Rahimi that a Syrian shell had fallen in Altınözü, Hatay Province.

[26][27] Immediately after this second incident in Hatay, artillery of the Turkish 3rd Border Battalion stationed in Yayladağı fired on Syrian military targets.

[27] A grain depot in Akcakale suffered minor damage from shrapnel from a Syrian mortar round exploding on 6 October 2012, though no injuries were reported.

Turkey responded by shelling Syrian military targets over the border and positioning a platoon of ACV-300 armored personnel carriers on the southern edge of Akçakale, with their weapons pointed at Tel Abyad, a town a few kilometres into Syria.

[22][28] On 8 October 2012, Altınözü was again hit by Syrian mortar fire, the six shells landed in a rural area causing no injury or loss of life.

[30][31] Inspectors claimed confiscating ammunition, military communications equipment and items "thought to be missile parts", however evidence has not been publicly shown.

[35][36] In the morning hours of 12 November 2012, a Syrian military helicopter bombed rebel positions around the town of Ras al-Ayn near the Turkish border across Ceylanpınar in Şanlıurfa Province.

[37] In the early hours of 14 January 2013, a shell fired by unknown Syrian forces landed in an olive grove near the border village of Akçabağlar, causing no casualties.

[46] Zahir Mulla and Muhammad Ahmad were killed along with other three men (whose identities couldn't be identified), when Turkish border guards opened fire.

[49][50] In May, there was a public scandal over video footage released by the newspaper Cumhuriyet purporting to show Turkish intelligence shipping arms to Syrian Islamist rebels.

[52] Also, the Russian Defense Ministry presented a video which claims that shows Turkish military shelling Syrian territory using heavy artillery positioned close to the border.

[citation needed] On 13 February 2016, Turkey began heavy artillery bombing of Kurds in North Aleppo and at Azaz as they advanced against opposition groups.

[55] Also, in a telephone call with German Chancellor Angela Merkel, Turkish Prime Minister Ahmet Davutoglu said Turkey will continue to strike back at Kurdish fighters in Syria.

[57] The Syrian government has accused Turkey, Qatar and Saudi Arabia of being behind a wave of bombings in the coastal cities of Tartous and Jableh.

[67][68] On 23 August, following the capture of a rebel pocket in the region, the Syrian Army fully encircled the Turkish observation post at Murak.

[69] In 2019, 29 Syrian Army soldiers were killed by Turkish Armed Forces and allied groups in North East Syria during Operation Peace Spring.

[70] Following Ankara's invocation of Article IV of the Washington Treaty, NATO's North Atlantic Council stated that the alliance: "... demands the immediate cessation of such aggressive acts against an ally, and urges the Syrian regime to put an end to flagrant violations of international law ...".