Aleppo: Syrian air strikes and shelling killed 25 civilians in eastern districts of Aleppo on Thursday, a monitor said, on the third day of a wide-ranging regime assault on rebel-held areas.
The bombardment hit at least six rebel-held neighbourhoods, said the Syrian Observatory for Human Rights.
At least 65 civilians have been killed in east Aleppo since the start of a regime offensive on Tuesday, said the monitoring group.
The renewed bombardment has shattered a month of relative calm in the devastated east of the divided northern city.
An AFP correspondent in the eastern districts said explosions from barrel bombs dropped by aircraft had been heard since 10:00 AM (0800 GMT).
One of the air strikes targeted a civil defence centre in the Bab al-Nayrab neighbourhood with no reported casualties, the correspondent said.
The Observatory said rebels responded with shelling of the city's government-controlled western neighbourhoods.
Once Syria's economic powerhouse, Aleppo has been roughly divided into a regime-controlled west and a rebel-held east since 2012.
No aid has entered the city's eastern neighbourhoods since government troops surrounded them in mid-July, and humanitarian organisations said this week food aid stockpiled there had all but run out.
The recent bombardment has ended a period of relative respite in east Aleppo, where regime ally Russia halted air strikes on October 18 ahead of a series of brief ceasefires.
Moscow said yesterday it had not carried out any raids on the city since that date.
Today, however, its defence ministry said it had bombed jihadist groups in Syria using cruise missiles launched from bombers deployed from Russian territory.
It said today's strikes targeted the Islamic State group and former Al-Qaeda affiliate Fateh al-Sham Front, but it did not specify where they had been carried out.
Russia said this week it was launching a major operation against IS and Fateh al-Sham Front, including in the northern province of Idlib.
The province is mostly controlled by a rebel alliance known as the Army of Conquest, which groups Islamist factions with jihadists of the Fateh al-Sham Front.
In Idlib, Russian strikes today killed six civilians from the same family including two children, the Observatory said.
The strikes were on the village of Kafr Jalis, the monitor said, where seven civilians including two children were also killed in Russian strikes on Tuesday.