Whole neighbourhoods of Syria's second city Aleppo have been flattened over the past year of conflict, with residents bombed from the air and abused on the ground, Amnesty said Tuesday.
"Aleppo has been utterly devastated, its people fleeing the conflagration in huge numbers," said Amnesty International's Senior Crisis Response Adviser Donatella Rovera.
The report came as the London-based group released satellite images of several Aleppo districts, taken before and after clashes between government and rebel forces broke out.
The images are part of an Amnesty analysis of the impact of the Syrian civil war on the northern city that was the country's commercial hub.
They show "alarming trends in how the conflict is being fought: with utter disregard for the rules of International Humanitarian Law, causing extensive destruction, death, and displacement," it said in a statement.
Aleppo became a battleground between rebels and troops in July last year, when opposition fighters in the neighbouring countryside staged an offensive.
Ever since, the city has fallen into a bloody stalemate, with much of eastern Aleppo in rebel hands and the west mostly under army control.
Daily battles are still being waged in the city, though much of the destruction was the result of "a campaign of indiscriminate air bombardment" by President Bashar al-Assad's loyalists, said Amnesty.
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Civilians living in opposition-controlled areas suffer daily from both government bombing raids and abuse at the hands of some opposition groups, it added.
"Countless civilians", it said, have been "killed and maimed" by government bombings.
"Government forces have relentlessly and indiscriminately bombarded areas under the control of opposition forces across Syria, with civilians being at the receiving end of such attacks and at the same time also being subjected to abuses by some armed opposition groups," said the watchdog.
The group published the testimonies of several civilians who have lost relatives due to the army's bombings.
"Yousef, seven, Mohammed, five, Ali, two, Hamza, 12, Zahra, 10, Husna, eight, Fatima, 10, Ahmad, seven, Abdel Karim, two, Hassan, 18 months... Why did they bomb here?... There were only civilians here. Our quarter was full of life, children playing everywhere," said Sara al-Wawi, who said she lost around 20 relatives in a March 18 air strikes.
"Now we are all dead, even those of us who are alive are dead inside, we have all been buried under this rubble," she said in the Amnesty report.
Amnesty also raised concern for Aleppo's ancient cultural sites, among them the damaged ancient souks and the destroyed minaret of the historic Umayyad mosque.
"Under international humanitarian law, parties to conflict are obligated to respect and preserve cultural property," said the group.
It said many of the conflict-displaced, especially to areas under rebel control, "receive little or no international aid, partly because they are in dangerous and difficult-to-access areas and also due to restrictions imposed by the Syrian government."
Amnesty reiterated its longstanding demand that the bloodshed in Syria, estimated to have cost more than 100,000 lives over the past 28 months, be referred to the International Criminal Court.