Air strikes have hit rebel-held eastern areas of Aleppo for the first time in three weeks, Syrian opposition activists say, amid fears it could signal the start of a new government offensive in the city.
The Britain-based Syrian Observatory for Human Rights said the air strikes struck three neighbourhoods, but had no immediate word on casualties.
Activist Baraa al-Halaby, based in eastern Aleppo, said warplanes fired missiles and helicopters dropped barrel bombs on the eastern part of Syria's largest city.
In mid-October, Russia said it would halt air strikes to allow rebels and supporters to leave eastern Aleppo.
The rebels refused to take up the offer and the United Nations failed to negotiate the delivery of aid into the besieged area.
UN agencies said today that food production in Syria has shrunk to "an all-time low", threatening to drive more people from their homes after more than five years of war.
The World Food Programme and the Food and Agricultural Organisation said factors like rising prices, poor weather, general instability and the lack of fertiliser and seeds could force some farmers to stop producing.
A joint report said the planting area in the 2015-16 season was the smallest ever in zones controlled by the government, ethnic Kurds and the armed opposition.
WFP spokeswoman Bettina Luescher said information was lacking about areas controlled by Islamic State.
FAO regional representative Abdessalam Ould Ahmed said 80% of households lack food or money to buy it.