Russia alleged on Friday that Ukraine had used U.S.-supplied rockets to kill women and children in a region of southern Russia, and said that Washington was to blame.
It was the first time that Russia has said it holds the United States responsible for civilian deaths on its own soil - an accusation that follows warnings by President Vladimir Putin that the West is playing with fire and risking a global conflict by letting Ukraine fire Western-supplied weapons into Russia.
Reuters could not independently verify the assertion and there was no immediate comment from Ukraine or the United States.
Foreign Ministry spokeswoman Maria Zakharova said the strikes had occurred last week in the Belgorod region shortly after the United States said it had agreed for the first time to let Ukraine fire U.S.-supplied weapons into Russia.
U.S. Secretary of State Antony Blinken confirmed on May 31 that President Joe Biden had approved the step so Ukraine could defend its Kharkiv region, which lies adjacent to Belgorod. The U.S. still bars Ukraine from firing U.S. weapons deeper into Russia.
Zakharova said statements by Washington giving the green light for such attacks amounted to "a confession...for the murder of children and women in the Belgorod region".
"Fragments of HIMARS (rockets) will serve as direct proof," she told reporters.
Zakharova did not present images of any rocket fragments. She did not say how many people had been killed in the alleged incident.
Putin has warned increasingly in recent weeks that the West risks a global conflict if it wades deeper into the Ukraine war. In remarks to foreign editors on Wednesday, he said Russia reserved the right to supply weapons to adversaries of the West in a "symmetrical" response to the Western arming of Ukraine.
