Amnesty International is demanding formal investigations into three American and Israeli attacks on densely packed suburbs in Tehran that killed at least 41 civilians, arguing the devastating impact and choice of weapons may amount to war crimes.
The advocacy group examined the March incidents, analysing photos and videos of the attacks available on social media as well as eyewitness accounts and official reports in Iranian state media to question the legitimacy of the strikes.
It found that the targets of the strikes, namely police stations and paramilitary compounds, may have been justified under international law.
But Amnesty said the damage to the surrounding areas, specifically civilian apartment blocks and businesses in congested neighbourhoods, should have been cause to rethink the attacks because of "entirely predictable consequences for civilians".
"Military combatants have to take feasible precautions to avoid civilian casualties," Andrew Witheford, a spokesperson for Amnesty International Australia, told the ABC.
"If it's possible, they need to give warning, and the strike itself and the action taken need to be proportionate to the military objectives that are being sought."
"Our analysis of these three attacks indicate that this bar wasn't cleared."
Amnesty, which describes the US and Israel's war with Iran as unlawful, said the two countries must allow independent investigations of their conduct relating to the three attacks, as well as the widely criticised strike on the Minab school on the very first day of the war which killed 150 people, including 120 children.
When asked whether those countries would launch independent investigations, Mr Witheford said: "It saddens me to say that it's not looking good so far."
'Horrific' scenes after early air strikes
One of the attacks investigated by Amnesty was on Niloufar Square in central Tehran on the evening of March 1, the second day of the war. A police station appeared to be the target, but significant damage was reported to nearby apartment buildings and shops in the area. Iranian officials said at least 20 civilians were killed in the strikes.
Amnesty said it had spoken to a local journalist, whom the organisation named "Kiana", who said that the scene was "horrific" and that between 15 and 20 apartment buildings had been damaged in the blasts. She told the organisation that a father and son working in a bakery were believed to be among the dead.
The second strike was on the Resalat neighbourhood in eastern Tehran, where Iranian officials said at least 16 people were killed, including 12 members of the same family, on the afternoon of March 9. The strike there appeared to target a building belonging to the Basij, the Iranian regime's notorious paramilitary branch of the Islamic Revolutionary Guard Corps (IRGC).
Amnesty's investigation revealed another three buildings were badly damaged, but the organisation could only verify one as being a residential block. One source it spoke to insisted the residents of the building, known as Number 12, were all civilians, and said he had seen horrific injuries and bodies blown to pieces.