In a new report, the London-based human rights group said some of the strikes launched by the regime in November 2014 on the city of Raqa gave "every indication of being war crimes".
The group said the strikes carried out between November 11 and 29 killed 115 civilians, including 14 children, and hit non-military targets including a mosque, a transport hub and a busy market.
Raqa city is the self-proclaimed capital of the brutal IS jihadist group in Syria, but Amnesty said there was no indication that militant positions were the target of the series of strikes.
"Syrian government forces have shown flagrant disregard for the rules of war in these ruthless air strikes," said Amnesty's Middle East and North Africa director Philip Luther.
"Some of these attacks give every indication of being war crimes," he added.
"The government appears indifferent to the carnage caused by these strikes, refusing even to acknowledge civilian casualties they have caused."
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Luther acknowledged that Raqa is a stronghold of IS jihadists, but said their presence did not justify attacks on civilian targets.
The group repeated a call for the war in Syria to be referred to the International Criminal Court, saying it would "send a message to all warring parties".
It also urged an arms embargo to "stem the flow of weapons being used to commit these crimes".
More than 215,000 people have been killed in Syria since March 2011, when anti-regime protests began, according to the Britain-based Syrian Observatory for Human Rights monitoring group.
The government put down the demonstrations with force and the situation spiralled into a brutal civil conflict.
Nearly a third of those killed in the conflict are civilians, and around half of Syria's population has been displaced by the war.