Around 70 bodies have been wrapped in carpets and plastic bags and placed in the mass grave since it was dug by the municipality on Tuesday.

A fraction of the at least 1,200 people who, according to Mariupol's mayor, have died since the city was besieged nine days ago.

Some of the people in the grave have died of natural causes, but about half are estimated by the AP's reporter to have been killed in the intense bombing that the city has endured.

"Disastrous situation"

MSF has previously described the situation in Mariupol as catastrophic, with a lack of food and water, electricity and heat.

Several attempts to evacuate civilians have been halted due to Russian troops violating the temporary ceasefire, according to Ukraine.

To the Guardian, the city's mayor Sergei Orlov says that the residents now live in "medieval" conditions and are forced to cook over an open fire after Russia blew up the gas pipelines.

He describes how residents fight over firewood and that snow is their only source of water.

Red Cross representative Sasha Volkov, also interviewed by The Guardian, describes how all shops and pharmacies have been emptied for several days.

And that many residents say they no longer have any food to give to their children.

- People started attacking each other over food.

They started smashing someone's car to get to the gas station.

Russia's actions are condemned

On Wednesday, a children's hospital in Mariupol was attacked and Ukrainian President Volodymyr Zelenskyj then spoke out strongly, calling it "the conclusive evidence that a genocide of Ukrainians is taking place."

Reactions have also been sharp in the rest of the world.

The Prime Minister of the United Kingdom Boris Johnson wrote on Twitter that Putin "will be held accountable for his horrific crimes", while the White House in a comment to Reuters called the attack "barbaric".

According to Reuters, Russian Foreign Minister Sergei Lavrov claims that the building was no longer a hospital, but had been occupied by Ukrainian "radical forces".

However, the Kremlin was more cautious and said that the incident was now being investigated.

Since the outbreak of the war, the World Health Organization (WHO) has verified 18 attacks on medical facilities in Ukraine.