Story highlights Russia had called for the ceasefire so people could evacuate Aleppo

The Syrian Observatory for Human Rights says it knows of no evacuations

(CNN) Mortar fire from regime forces struck the al-Mashhad neighborhood of eastern Aleppo on Saturday evening as a three-day Russian-backed ceasefire came to an end at 7 p.m. (noon ET), according to the activist Aleppo Media Center.

The Russian Defense Ministry had called for the ceasefire -- termed a "humanitarian pause" -- so rebels, civilians and medical cases could evacuate Aleppo during daylight hours without fear of being struck by bombs.

But it appears few, if any, actually left the besieged city.

The UK-based Syrian Observatory for Human Rights said Saturday it didn't know of anybody who evacuated using any of the eight corridors announced by the Syrian regime and Russia.

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Thousands of families tried to leave the eastern neighborhoods via the Bustan al-Qassr corridor but were prevented by the rebels, who opened fire to disperse them, reported SANA, the Syrian state news agency.

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