Russia has said Ukraine fired US-supplied long-range missiles into the country for the first time on Tuesday.
Ukraine used Atacms missiles in a strike on Russia's Bryansk region this morning, the Ministry of defence in Moscow said.
Five missiles were shot down and one damaged, with its fragments causing a fire at a military facility in the region, it said in a statement.
Use of the US missiles was also reported in Ukrainian media, but Ukraine has not yet commented.
