
At least four children were among the injured, acting Sumy mayor Artem Kobzar said on the Telegram messenger app.
He did not identify the industrial facility.
“The enemy launched a missile strike on the city centre. Several high-rise buildings, and a school are damaged. Children were in a shelter,” the Sumy region’s governor Volodymyr Artiukh said from the site in a video posted on Telegram.
Heavy black smoke and fires could be seen in the background, as well as a car with shattered windows.
Smoke also rose from the upper floors of a five-storey residential block nearby.
Sumy, about 30km from the Russian border, as well as the surrounding region, is subject to constant drone and missile strikes by Russia.