A video of a Chinese woman who calls herself an opera singer and performs at the ruins of a theater in Mariupol is circulating on the Internet, causing outrage in Ukraine, Sky News reports.

The theater in Mariupol was destroyed by Russian aircraft in March of last year.

Singer Wang Fang was accompanied by several Chinese bloggers who entered the city, which is now under the control of the Russian Federation.

Ukraine has officially demanded an explanation from Beijing regarding this incident, Kyiv Post reports.

Yesterday, the exiled adviser to the mayor of Mariupol, Petro Andryushchenko, published a video of the woman’s speech on his Telegram channel.

“Haven’t there been round dances on the graves of Mariupol residents for a long time? Here they are,” he said.

“The Russians brought the so-called ‘famous’ Chinese opera singer Wang Fang to Mariupol—so famous that even Google doesn’t recognize her—and she performed Katyusha in the ruins of the Drama Theater.”

He added: “I hope the spirits of the more than 600 residents of Mariupol killed by the Russians liked it so much that they will haunt her for the rest of her life.”