A Russian military transport plane crashed Wednesday in a border region near Ukraine, and Moscow accused Kyiv of shooting it down, saying all 74 people aboard were killed, including 65 Ukrainian prisoners of war headed for a swap. Russia offered no evidence and Ukraine didn't immediately confirm or deny it.

Video of the crash on social media from the Belgorod border region of Russia showed a plane falling from the sky in a snowy, rural area, and a massive ball of fire erupting where it apparently hit the ground.

The Associated Press couldn't confirm who was aboard or other details on what brought the plane down.

Throughout the 700-day war, Russia and Ukraine have traded conflicting accusations, and establishing the facts has often been difficult, both because of the constraints of a war zone and because each side tightly controls information.

The Russian Defense Ministry said in a statement that the Il-76 transport plane was carrying 65 POWs, a crew of six and three Russian servicemen. Russian radar registered the launch of two missiles from Ukraine’s Kharkiv region that borders Belgorod, the statement said.

“We’ve seen the reports, but we’re not in any position to confirm them,” U.S. National Security Council spokesman John Kirby said.

Separately, a U.S. official said that it’s not clear that there were actually Ukrainian POWs aboard the aircraft that crashed. The official spoke on condition of anonymity to provide details that haven't been announced publicly.

Hours after the crash, the General Staff of the Armed Forces of Ukraine made no mention of the crash in a statement. But it added that Ukraine targets Russian military transport planes believed to be delivering missiles, especially near the border.

Russia lost two warplanes and two helicopters in its own airspace in one day in May 2023. Kyiv officials initially denied involvement, but later said they had used Patriot missiles to hit the aircraft.

The Kharkiv and Belgorod regions have long been a focus of the fighting between the neighbors, including airstrikes with missiles and drones.

The Russian military said that the POWs were being flown to the region for a prisoner swap when the plane was downed at 11:15 a.m. local time. The Il-76 is designed to carry up to 225 troops, cargo, military equipment and weapons, according to Russia’s military export agency.

Ukrainian military intelligence confirmed a swap was due to take place, but said that it had no information about who was on the plane. Moscow didn't ask for specific airspace to be kept safe for a certain length of time, as has happened in past exchanges, it said in a statement.

At a news conference at the United Nations, Russian Foreign Minister Sergey Lavrov called for an emergency meeting later Wednesday of the U.N. Security Council, saying he has “no concern” about the international community believing Moscow's allegations.

But the U.N. Security Council already has a meeting scheduled to hear from many countries that didn’t get to speak at Tuesday’s ministerial meeting on the Israeli-Hamas war, and France, which holds the council's presidency, indicated that the emergency meeting will take place on Thursday at 5 p.m.

Russian officials and lawmakers questioned whether there should be further prisoner swaps between Moscow and Kyiv. The most recent one, brokered by the United Arab Emirates, took place this month and was the biggest to date, with 230 Ukrainian POWs returning home and 248 Russians released. It was the first in almost five months and the 49th of the war.

Russia has largely ensured its air dominance during the war against Ukraine's fleet of Soviet-era warplanes. But Russia has suffered a series of crashes that some observers have attributed to a higher number of flights amid the fighting in Ukraine.

At the same time, Kyiv has boasted of shooting down two Russian command and control planes, which would be a major feat for Ukraine if true. Cross-border attacks on Russia’s Belgorod region also have increased, with the deadliest one killing 25 people in December.

Shortly before the crash, Belgorod Gov. Vyacheslav Gladkov said on his Telegram channel that a “missile alert” had been triggered in the region.

Ukraine’s Coordination Headquarters for the Treatment of Prisoners of War said that it was looking into the crash, but didn't immediately provide any information. Instead, it cautioned against sharing “unverified information.”

“We emphasize that the enemy is actively conducting information special operations against Ukraine aimed at destabilizing Ukrainian society,” it said in a statement on Telegram.

Russian President Vladimir Putin’s spokesman, Dmitry Peskov, told reporters in the morning that he couldn't comment on the crash, because he didn't have enough information about it. There was no comment from the Kremlin later in the day.

The 1,500-kilometer front line in the war has been largely static amid a second winter of fighting. As both sides seek to replenish their weapons stockpiles, the war recently has focused on long-range strikes.

Earlier, Ukrainian President Volodymyr Zelenskyy said that a major Russian missile attack on Tuesday had killed 18 people and injured 130 others.

The barrage, employing more than 40 ballistic, cruise, anti-aircraft and guided missiles, hit 130 residential buildings in three Ukrainian cities, “all ordinary houses,” Zelenskyy said on X, formerly known as Twitter.

Russia’s onslaught, which included targets in Kyiv and the second-largest city of Kharkiv, was the heaviest in weeks and lent weight to Zelenskyy’s appeals for Western allies to provide more military aid.

“This year, the main priority is to strengthen air defense to protect our cities and towns, as well as defend front-line positions,” Zelenskyy tweeted Tuesday.

Analysts say Russia has stockpiled missiles to pursue a winter of aerial bombardment, while Ukraine has sought to strike inside Russia with new types of drones.

Russia may have employed decoy missiles in Tuesday’s attack in an effort to open up holes in Ukraine’s air defenses, a U.S. think tank said.

The Washington-based Institute for the Study of War said that Moscow is likely trying to acquire more ballistic missiles from foreign countries, including Iran and North Korea, because they may be more effective in some circumstances.

A further barrage of Russian S-300 missiles struck residential districts of Kharkiv late Tuesday, wounding nine people and damaging residential buildings, regional Gov. Oleh Syniehubov said.

Russia denies its forces strike civilian areas, although there is substantial evidence to the contrary.

Also on Wednesday, the Russian Defense Ministry said that its air defenses shot down four Ukrainian drones in the Oryol region of western Russia. Oryol Mayor Yuri Parakhin said that several drones were downed over the city with no casualties.

Another Ukrainian drone was downed early Wednesday over the Belgorod border region, according to Gladkov. He said that there were no casualties or damage.

Two Ukrainian drones were downed over the Bryansk region in the evening, Gov. Alexander Bogomaz said.

Ukraine’s allies have promised more military aid even though their resources are stretched. Help from the United States, by far Ukraine’s single biggest provider, has also hit political snags.

The German Defense Ministry said Wednesday that it plans to send six Sea King Mk41 helicopters to Ukraine.