Russia's government has summoned the US ambassador to Moscow to protest a deadly Ukrainian attack on Crimea, which it says employed US-supplied ATACMS missiles.
Russia's foreign ministry on Monday summoned US envoy Lynne Tracy over the attack, in which its defense ministry said five long-range ATACMS missiles equipped with cluster warheads were used.
Moscow-installed authorities in Sevastopol said the Sunday attack killed four people and injured 153, including children.
The foreign ministry told the envoy that the United States has actually become a party to the conflict by supplying Ukraine with the most advanced weapons.
The ministry also said the US bears "equal responsibility" with Ukraine for the attack. It warned that "retaliatory measures are certain to follow."
Ukrainian presidential adviser Mykhailo Podolyak defended the attack, saying on Monday that Crimea is definitely a territory occupied by Russia and is the site of a full-scale war.
Meanwhile, authorities in the eastern Ukrainian region of Donetsk said the town of Pokrovsk was hit with two Russian short-range Iskander missiles. At least four people were killed and 34 others, including children, injured, officials said.