Intense air strikes have resumed in rebel-held districts of eastern Aleppo after a weeks-long pause, killing at least three people.
Syrian state television said the Damascus government's air force took part in strikes against "terrorist strongholds" in Aleppo's Old City, while Russia said it had struck Islamic State and former Nusra Front sites elsewhere in Syria, without mentioning Aleppo.
The bombardment appeared to mark the end of a pause in strikes on targets inside the city declared by Syria's government and Russia on October 18.
"Our houses are shaking from the pressure. Planes are soaring above us and the bombardment is around us," said Modar Shekho, a resident of eastern Aleppo. Both rocket strikes by jets and barrel bombs dropped by helicopters were used, residents and a war monitor said on Tuesday.
State-owned Ikhabariyah television reported large troop deployments along several main fronts in the Aleppo theatre in preparation for a major ground offensive that it said was imminent and awaiting "zero hour" to begin.
The renewed violence in Aleppo will be closely followed in Washington where President-elect Donald Trump has signalled he intends to take a different approach to Syria from that of President Barack Obama, who has backed some rebel groups.
Trump and Russian President Vladimir Putin, whose approach in Syria has been praised by the US president-elect, spoke by phone on Monday and agreed to "combine efforts to tackle international terrorism and extremism", the Kremlin said.
Aleppo has become the fiercest front in Syria's five-and-a-half-year war, pitting President Bashar al-Assad, supported by Russia, Iran and Shi'ite militias against Sunni rebels including groups backed by Turkey, the United States and Gulf monarchies.