The fire "has completely engulfed the building — 10,000 square meters," Zelenskyy said.
Ukrainian Interior Minister Ihor Klymenko said at least 15 more people were missing.
"Rescuers are at the spot, saving people. Extinguishing [the fire] is complicated by the presence of a significant amount of flammable materials and the possible further spread of the fire to nearby warehouses," Klymenko said in a statement.
The attack happened just two days after Russian forces struck a local printing house in Kharkiv with several missiles, killing seven workers and injuring more than 20. The attack also destroyed 50,000 Ukrainian books.
"If Ukraine had sufficient air defense systems and modern combat aircraft, Russian strikes like this one would have been impossible," Zelenskyy said in his post on Saturday. "And that is why we appeal to all leaders, to all states: We need a significant enhancement of air defense and sufficient capabilities to destroy Russian terrorists," he said.
