Russia has accused Ukraine of playing a "key role" in an anti-Israel riot at an airport in the Muslim-majority region of Dagestan.
"The criminal Kyiv regime played a direct and key role in carrying out the latest destructive act," Russia's foreign affairs spokeswoman Maria Zakharova said in a statement.
Russian police said they had arrested 60 people suspected of storming the airport, seeking to attack Jewish passengers coming from Israel.
Dozens of protesters, many of them chanting "Allahu akbar" (God is greatest), broke through doors and barriers at Makhachkala airport yesterday, with some charging onto the runway.
A senior Ukrainian official has said Kyiv had nothing to do with the unrest, rejecting Russia's accusation as groundless.
"Of course, Ukraine has nothing to do with the latest large-scale surge of xenophobic sentiments on the territory of the Russian Federation," Ukrainian presidential adviser Mykhailo Podolyak told Reuters in a written statement.
Earlier Russia blamed "external interference" for the riot.
"Yesterday's events at Makhachkala airport are, to a large extent, the result of external interference," Kremlin spokesman Dmitry Peskov told reporters.
"Against the backdrop of TV footage showing the horrors of what is happening in the Gaza Strip - the deaths of people, children, old people, it is very easy for enemies to take advantage of and provoke the situation," Mr Peskov told reporters.
The Kremlin did not provide further details on its claim of "external interference".
State media earlier cited Dagestan's governor as saying the "initiators of this action are our enemies who organised it from Ukrainian territory."
In response to the events, President Vladimir Putin was due to hold a meeting with his top advisers, including the defence minister and spy chiefs, later today to discuss "the West's attempts to use the events in the Middle East to split Russian society," Mr Peskov said.
