Russia presented all evidence on aid convoy attack, now wants impartial investigation – Lavrov

"There was another unacceptable provocation on September 19 - the shelling of a humanitarian convoy near Aleppo,” Lavrov said.

He also noted that at the same time militants had advanced in the 1070 district of Aleppo.

“I am confident that such coincidences require serious analysis and an investigation.”

On September 19, a humanitarian convoy consisting of 31 trucks was attacked while heading to Aleppo. According to the Red Cross, 20 civilians and one aid worker died as a result. Initial reports by the organization claimed the convoy had been targeted by an airstrike.

On Tuesday, the UN backtracked on its earlier claims that the convoy was hit by military planes.

"We are not in a position to determine whether these were in fact airstrikes. We are in a position to say that the convoy was attacked," UN humanitarian spokesman Jens Laerke said.

Speaking on the delivery of humanitarian aid to Syria, Lavrov said that the Russia and US-backed plan included the creation of a demilitarized zone around the Castello Road near Aleppo. The minister added that while the Syrian government forces have started their withdrawal, the militants have not followed suit.

"The government forces began their withdrawal – in accordance with the Russia-American agreements - only to see that the opposition does not follow suit, and even begins to fire."

Russia has informed the US of some 300 ceasefire violations by the rebel groups in Syria, including those of Ahrar al-Sham.

"We notified our American colleagues about 300 cases of violation of the cessation of hostilities on the part of Ahrar al-Sham and a number of other opposition groups whose names have been mentioned in the list of those [groups] who joined the ceasefire,” Lavrov said.

US Secretary of State John Kerry said that following the attack on the humanitarian convoy near Aleppo, the parties involved in the cessation of hostilities in Syria “cannot do business as usual.”

He stressed that without a proper ceasefire in Syria the country will witness “more dead and more suffering on an even greater scale.”

The US secretary of state put the blame for violations of the ceasefire on Syrian President Bashar Assad, calling him a “spoiler.” Kerry added that in his view, Assad “does not believe in ceasefire.”

Kerry also urged that Syrian government forces should be banned from flying over territories held by the opposition forces.