PARIS >> Evidence suggests twin Russian airstrikes deliberately targeted a theater being used as a shelter in the besieged city of Mariupol, the rights group Amnesty International said in a report released Thursday.

The report condemned the attack as a war crime. Amnesty said there was no evidence that the Donetsk Academic Regional Drama Theater was a base of operations for Ukrainian soldiers and every indication that it was a haven for civilians seeking protection from weeks of relentless shellings and airstrikes.

The March 16 airstrike devastated the building, collapsing its rear and side walls directly onto a field kitchen used as a community gathering space for food, water and scarce news about evacuations and the war.

City officials initially estimated around 300 dead. An Associated Press investigation found the attack may have killed closer to 600 people inside and outside the building. Most of the two dozen survivors and witnesses AP interviewed put the number even higher.

Researchers for Amnesty International identified 12 of the dead.

Those who bore witness “saw bodies, remains of bodies. And that’s how we can try to reconstruct. But the truth is that we will never know the truth. We will never get the final figure. And what is more or horrifying for me is that we will never know the whole names,” said Oksana Pokalchuk, Amnesty’s director general for Ukraine.

The Amnesty team interviewed 52 survivors and first-hand witnesses, about half of whom were either in the theater or nearby. Using satellite imagery from that morning, they determined that the sky was consistently clear enough for any pilot to see the word “CHILDREN” written in giant Cyrillic letters in the building’s front and back.

Physicists and weapons analysts examined imagery of the debris and determined that two 500 kilogram bombs dropped from a Russian jet were the most likely munition. Their finding was consistent with the testimony from multiple witnesses who told The Associated Press they had heard two explosions.

Thursday’s report suggested the toll was not as high as the one cited by either AP or the city, citing some witnesses who believed the building had emptied due to evacuations in the two previous days.

However, while two days of evacuations from Mariupol on March 14 and 15 had indeed emptied the theater, newcomers immediately filled the space again, according to nearly all the witnesses interviewed by the AP, including a family that arrived on the morning of March 16 to find no space for them and a man who worked at the “check-in” area on the ground floor.

AP created a 3D model of the building’s floorplan reviewed repeatedly by direct witnesses, most from within the theater, who described in detail where people were sheltering. All the AP witnesses said at least 100 people were at the field kitchen just outside, and none survived. They also said the rooms and hallways inside the building were packed.

By the time the theater was struck, Mariupol’s thousands of residents had been without electricity, running water or Internet for over two weeks. Families lost touch with each other, and many remain out of touch to this day, giving people no way to learn whether a loved one is alive or dead.

A Telegram chat for people seeking out the missing has thousands of names from Mariupol, and the toll of the war on the city will likely never be known.

In the days after the airstrike, Russian forces took control of the city center. The theater was bulldozed and any remains were taken to the ever-growing mass graves in and around Mariupol.