Local authorities in the eastern Ukrainian city of Sloviansk told residents to go out as little as possible and to keep their windows shut on Wednesday because Russian shelling had damaged a warehouse storing ammonium nitrate nearby.
Ammonium nitrate is most commonly used as a source of nitrogen for fertiliser and it can cause respiratory problems if inhaled in large quantities. Russia did not immediately comment on the report and Reuters could not verify it.
"We emphasise that there is no direct threat to the lives of the inhabitants of the Sloviansk community," the Sloviansk city authorities said, adding that the warehouse was in the Kramatorsk area.
(Reporting by Natalia Zinets, Editing by Timothy Heritage)