At least 37 people are confirmed to have died in a fire that tore through a shopping centre in the Siberian city of Kemerovo.
Russian media say at least 64 others, including as many as 41 children aged between two and 17, are missing.
The blaze started on an upper floor of the Winter Cherry complex and many of the victims were in a cinema.
Video posted on social media showed people jumping from windows to escape the flames on Sunday.
Smoke billowed from windows as fire crews worked to evacuate the property.
Kemerovo, a key coal-producing area, lies about 3,600km (2,200 miles) east of Moscow.
The cause of the blaze is not yet known but authorities have launched an investigation.
Austrian Chancellor Sebastian Kurz has offered his condolences to the families and friends of the victims, as did Latvian Foreign Minister Edgars Rinkēvičs.