Intensified Russian and Syrian bombing of besieged rebel-held parts of Aleppo in the past weeks has hit hospitals, bakeries and water pumping stations, and killed hundreds of civilians. Waiting buses were shown on state television.
The airstrikes north of Aleppo had targeted Kurdish militia in the Maarraat Umm Hawsh region, said Turkey's state-run news agency Anadolu.
The United Nations had proposed allowing safe passage for jihadist fighters linked to al-Qaida from eastern areas of Aleppo, where they intermingle with anti-Assad forces backed by the USA, some European nations and allies in the Middle East.
Speaking in Geneva, Egeland also says the Russian government is considering a United Nations request to extend the planned three-day string of temporary, 11-hour daily pauses in fighting to a fourth day.
European Union leaders yesterday gathered for a summit in Brussels were to strongly condemn Syria and Russian Federation over Aleppo and were weighing sanctions.
On Wednesday, Syria's foreign ministry had said troops would pull back to facilitate the exit of rebel fighters, who had also said they would not leave eastern Aleppo, the last major urban center controlled by opposition forces in Syria.
The 250,000 civilians trapped inside the besieged rebel held parts of the city have so far stayed away from the corridors.
Gunfire and artillery exchanges erupted around a crossing point near the rebel-controlled Bustan al-Qasr district shortly after the pause began, an AFP correspondent said.
"An appeal to our people. we will extend every help from shelters to hot dishes and facilities that offer you medical treatment", said the army loudspeaker.
Putin said he told German and French presdients that Russian Federation was "intending to extend as far as possible" a halt to its air raids in Syria's second city, in order to allow civilians and militants to leave the devastated city.
Describing the late night talks as "very tough", Merkel said they "gave Germany the clear chance to define what constitutes a war crime".
"It's going to be the springboard, as a big city, to move to another areas, to liberate other areas from the terrorists", Assad told Russian tabloid Komsomolskaya Pravda in an interview this month.
"It's vital that we work together to continue to put pressure on Russian Federation to stop its appalling atrocities, its sickening atrocities, in Syria", she said.