Aleppo, Syria's largest city and once commercial center, has been the center of violence in recent weeks but was not part of the latest partial truce.
Syrian state TV said shells hit a government-held area during morning during rush hour, killing seven people and wounding at least 35, while activists reported two dead in a rebel neighborhood.
The Observatory said more than 50 were wounded, including some who were in critical condition, which could raise the death toll.
The Observatory and another activist group, the Local Coordination Committees, said government forces also shelled rebel-held parts of the city on Tuesday, killing two and wounding several.
The Observatory said more than 250 civilians have been killed in 12 days of violence in both government- and rebel-held parts of the city.
Also in northern Syria, warplanes carried out intense airstrikes on the city of Raqqa, the de facto capital of the extremist Islamic State group, in the early hours today.
The Observatory, which has a network of activists around the country, said there were more than 35 air raids and that 18 people were killed including five members of the Islamic State group. It said dozens were wounded.
The anti-IS group Raqqa is being Slaughtered Silently, said the airstrikes killed 10 and wounded dozens - but different casualty figures are common in the chaos of Syria's civil war. The group said there were calls from mosque loudspeakers for the residents to donate blood.
