Foreign Affairs Minister John Baird issued a statement that condemned the ongoing barrage as appalling.
Tuesday's attack was part of a 10-day offensive by Syrian President Bashar Assad's air force on the city, which activists say has resulted in the deaths of 360 people.
Baird called the use of force deplorable, and urged rebels and government forces to allow emergency relief workers safe passage.
The U.S. and Britain also condemned the ongoing attacks on Monday.
The Syrian conflict has claimed 120,000 lives since March 2011.
"The appalling level of violence the Assad regime continues to inflict on the Syrian people will only stoke further violence and brutality on both sides of the conflict," Baird said.
"Canada's position has been clear: the only way to end the crisis in Syria is through a Syrian-led political transition. The Syrian people must believe that they have a place in a new, free, democratic and pluralistic Syria."
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