Mariupol City Council, who shared an image of the destroyed building, said Russian forces had “purposefully and cynically destroyed the Drama Theater in the heart of Mariupol.”
“The plane dropped a bomb on a building where hundreds of peaceful Mariupol residents were hiding,” it said.
CNN has geolocated the image and confirmed it is of the theater in the southeastern port city.
Videos of the aftermath showed a fire raging in the theater’s ruins. The number of casualties is unknown, authorities said.
“It is still impossible to estimate the scale of this horrific and inhumane act, because the city continues to shell residential areas,” the council wrote on Telegram. “It is known that after the bombing, the central part of the Drama Theater was destroyed, and the entrance to the bomb shelter in the building was destroyed,” it added.
Petro Andruishchenko, an adviser to the mayor of Mariupol, described the theater as the largest shelter “in number and size” in the city’s center. “According to preliminary data, more than a thousand people were hiding there,” he said. “The probability of getting there to dismantle the rubble is low due to constant shelling and bombing of the city.”
The theater attack comes just a day after a Ukrainian official accused Russian troops of holding some 400 people captive at Mariupol’s Regional Intensive Care Hospital.
“It is impossible to find words that could describe the level of cruelty and cynicism with which the Russian occupiers are destroying the civilian population of the Ukrainian city by the sea. Women, children, and the elderly remain in the enemy’s sights. These are completely unarmed peaceful people,” the city council said.
“We will never forgive and never forget,” it added.
Mariupol has been reduced to a battle zone, with the city’s deputy mayor telling CNN on Tuesday that Russia has been bombarding the city with missiles, saying that they counted 22 aircraft on Monday “which were bombing our city, and at least 100 bombs.”
Residents who fled the city have described conditions there as “unbearable” and “just hell.” On Tuesday, shocking drone footage and satellite photos showing rising plumes of thick smoke and destroyed buildings emerged, underscoring the sheer devastation wrought by the Russian bombardment.
As many as 2,500 civilians have died in Mariupol, Ukrainian officials estimate, and hundreds of thousands of people are trapped in the city — with officials warning those who remain are without electricity, water and heat.
CNN’s Ivana Kottasová, Jack Guy and Paul P. Murphy contributed to this piece.