According to a diplomatic source on Thursday, Syrian regime forces and opposition fighters agreed on a cease-fire in eastern Aleppo after Causoglu spoke over the phone with Russian Foreign Minister Sergei Lavrov, Qatari Foreign Minister Sheikh Mohammed bin Abdulrahman Al-Thani, Saudi Arabian Foreign Minister Adel al-Jubeir.

On Tuesday evening, regime forces and opposition groups agreed to a Turkey-brokered cease-fire deal with a view to evacuating civilians from the eastern part of the city.

Turkish and Russian presidents spoke over the phone about Aleppo on Wednesday after Cavusoglu's efforts, the source, who spoke on condition of anonymity due to restrictions on talking to the media, said.

Recep Tayyip Erdogan and Vladimir Putin discussed the human tragedy in Aleppo and bilateral relations between Turkey and Russia, the source said.

The two leaders agreed the partial cease-fire deal should be implemented completely and no violations should take place, the source added.

Earlier on Thursday, Iranian-backed Shia militias broke the cease-fire when they opened fire on a convoy carrying civilians to the opposition-held Idlib province. At least four civilians were killed in the attack.

After cease-fire was violated, Cavusoglu spoke with his Iranian counterpart Javad Zarif two times over the phone.

Violence escalated in Aleppo city on Monday when Syrian regime forces advanced into opposition-held parts of eastern parts of the city following a five-month siege and persistent aerial bombardment.

The Russian-backed regime had been trying to reestablish control over parts of Aleppo captured four years ago by armed opposition groups.

Syria has been locked in a devastating civil war since early 2011 when the regime cracked down on pro-democracy protests – which had erupted as part of the Arab Spring uprisings – with unexpected ferocity.

Since then, hundreds of thousands of people are believed to have been killed by the conflict and millions more displaced.

Anadolu Agency