A Russian military plane has crashed on the Ukraine-Russia border, with Moscow saying 65 Ukrainian prisoners of war were onboard.
Its defence ministry confirmed the Ilyushin Il-76 transporter crashed in the Russian city of Belgorod on Wednesday morning.
"They [the prisoners of war] were being transported to the Belgorod region for exchange," it added.
Another six crew members and three other people were also said to be on board.
In a later statement, posted on Telegram, the defence ministry blamed Kyiv for the crash, which it labelled a "terrorist attack".
"The plane was destroyed by the Ukrainian Armed Forces from the area of Liptsy, Kharkiv region, using an anti-aircraft missile system," the ministry said.
Ukraine has yet to confirm or deny whether it was involved or if any prisoners of war were on the plane, and has urged people to "refrain from spreading unverified information".
Ukraine war latest: Military plane crashes in Russia
Retired general Andrei Kartapolov, a member of the Russian parliament, alleged that the incident involved missiles of the type that have been supplied to Ukraine by the West, the news agency Reuters reported.
Mr Kartapolov did not state the source of his information, and said investigations would confirm whether the missiles were Patriots or IRIS-Ts.
Speaking on his morning call with reporters, Vladimir Putin's spokesperson, Dmitry Peskov, said he could not comment on the crash as he did not have enough information about it.
Andrii Yusov, from the Main Directorate of Intelligence in Ukraine, told the Ukrainian news outlet Radio Liberty, that a planned prisoner exchanger with Russia was "currently not taking place" following the crash.
A Russian Aerospace Forces commission has "flown to the crash site in order to establish the causes of the disaster", according to the defence ministry.
Sky's defence and security analyst Professor Michael Clarke, cast doubt on the Russian claims, as the plane appeared to be "in one piece" as it came down over Belgorod.
He said footage of the crash shows "an aircraft that's pretty well in one piece".
"If it had been hit by three missiles, as the Russians originally said, it certainly wouldn't be in one piece," he says.
Belgorod, a region along the Russia-Ukraine border, has come under several attacks in the last few months.
Earlier on Wednesday, Ukraine's president, Volodymyr Zelenskyy said a major Russian missile attack that was apparently devised to overwhelm the country's air defences had killed 18 people and injured 130.
The barrage employing more than 40 ballistic, cruise, anti-aircraft and guided missiles early on Tuesday hit 130 residential buildings in three Ukrainian cities, "all ordinary houses", Mr Zelenskyy said on X, formerly Twitter.
The air strikes included targets in the capital Kyiv and Ukraine's second-largest city, Kharkiv.
Russia has denied targeting civilians.
It comes after Ukraine claimed it had shot down two high-value Russian aircraft earlier this month.
The Ukrainian army said an A-50 spy plane - one of just a handful of early warning and control planes in the Russian fleet - and an Ilyushin Il-22 airborne command post had been destroyed.
Both were shot over the Sea of Azov, according to Ukrainian government adviser Anton Gerashchenko.
Officials estimate A-50s - which typically holds a 15-strong crew - are worth about £260m ($330m).