By Sam Hancock & Elsa Maishman
Ukraine has confirmed it carried out a strike in the occupied region of Donetsk, which it earlier claimed killed 400 Russian troops.
Russian officials contested the figure, saying only 63 troops were killed. Neither claim has been verified, and access to the site is restricted.
The attack on New Year’s Day hit a building in the city of Makiivka, where Russian forces were stationed.
It is extremely rare for Moscow to confirm any battlefield casualties.
But this was such a deadly attack, says the BBC’s Russia editor Steve Rosenberg, that staying silent most probably wasn’t an option.
It is the highest number of deaths acknowledged by Moscow in a single incident since the war began ten months ago.
In a statement on Monday, Russia’s defence ministry said Ukrainian forces fired six rockets using the US-made Himars rocket system at a building housing Russian troops. Two of them were shot down, it added.
A number of Russian commentators and bloggers acknowledged the attack – but said the numbers were lower than claimed by Ukraine.
But Igor Girkin, a pro-Russian commentator, said hundreds had been killed and wounded, although the exact number was still unknown because of the large number still missing.
The building itself was “almost completely destroyed”, he said.
He added that the victims were mainly mobilised troops – that is, recent conscripts, rather than those who chose to fight. He also said ammunition was stored in the same building as the soldiers, making the damage worse.
“Almost all of the military equipment was also destroyed, which stood right next to the building without any disguise whatsoever,” he wrote on Telegram.
Girkin is a well-known military blogger, who led Russian-backed separatists when they occupied of large parts of eastern Ukraine in 2014. He was recently found guilty of murder for his part in the shooting down of flight MH17.
Despite his pro-Russian stance, he regularly criticises the Russian military leadership and their tactics.
According to the Ukrainian military’s earlier statement, 300 were wounded in addition to the estimated 400 killed. Ukraine’s army claims, almost daily, to have killed dozens, sometimes hundreds, of soldiers in attacks, so caution is needed.
A later statement from the Ukrainian military’s general staff said “up to 10 units of enemy military equipment” were “destroyed and damaged” in the strikes, and that “the losses of personnel of the occupiers are being specified”.
Ukraine has not confirmed the strikes were carried out with Himars missiles, maintaining a long-held strategy of not releasing specific details about its attacks.
Hours after the strike in Makiivka, Kyiv came under fire. A drone and missile attack targeted critical infrastructure, the Ukrainian capital’s regional governor Oleksiy Kuleba said.
One man in Kyiv was injured by debris from a destroyed Russian drone, the capital’s mayor added.
Mr Kuleba said the weapons were Iranian-made Shahed drones, adding that they were “targeting critical infrastructure facilities”.
“The main thing now is to stay calm and stay in shelters until the alarm is off,” he said.
All 39 Iranian made drones were eventually shot down by Ukraine, the military said. But Vitaly Klitschko, the mayor of Kyiv, said energy facilities were damaged, disrupting power and heating supplies.
Russia has been targeting Ukraine’s energy infrastructure for several months, destroying power stations and plunging millions into darkness during the country’s freezing winter.