Kyiv (Ukraine) (AFP) - Ukraine on Sunday denounced as dangerous lies suggestions from Russia that it was preparing to use a "dirty bomb".
Its western allies also dismissed the allegations from Moscow, just hours after Russia went public with the claims.
In conversations with his British, French and Turkish counterparts, Russian Defence Minister Sergei Shoigu conveyed "concerns about possible provocations by Ukraine with the use of a 'dirty bomb'", Moscow said.
Russia did not mention the alleged "dirty bomb" allegation in its statement following Shoigu's call with Pentagon chief Lloyd Austin.
"If Russia calls and says that Ukraine is allegedly preparing something, it means one thing: Russia has already prepared all this," President Volodymyr Zelensky said in a video address on social media.
"I believe that now the world should react as harshly as possible."
Earlier Sunday, Ukraine's Foreign Minister Dmytro Kuleba denounced Moscow's claims as "absurd" and "dangerous".
"Russians often accuse others of what they plan themselves," he added.
A British defence ministry statement said Defence Secretary Ben Wallace had "refuted these claims and cautioned that such allegations should not be used as a pretext for greater escalation".
And in Washington, National Security Council spokeswoman Adrienne Watson dismissed Moscow's "transparently false" claim.
"The world would see through any attempt to use this allegation as a pretext for escalation," she added.
'Vile strikes'
Russia also announced Sunday that it had destroyed a depot in central Ukraine storing over 100,000 tonnes of aviation fuel.
Kyiv's energy operator meanwhile said scheduled power cuts had been introduced in the Ukrainian capital due to Russia's repeated strikes on the nation's power network.
The blackouts started from 11:13 am (0813 GMT) with consumers in Kyiv divided into three groups "disconnected for a certain period of time", energy company DTEK said.
DTEK reiterated calls for residents to use electricity "sparingly" and for businesses to limit their use of external lighting.
More than one million Ukrainian households have lost electricity following recent Russian strikes, according to the Ukrainian presidency, at least a third of the country's power stations having been destroyed ahead of winter.
Zelensky condemned the "vile strikes" in comments late Saturday, after Russian attacks caused power cuts across the country.
'Save your strength'
In the southern Ukrainian city of Kryvyi Rig, deputy mayor Sergiy Miliutin was dealing with emergencies and power outages from his underground bunker, used as a venue for a children's martial arts competition.
"I've reached a point where I just survive on my drive.You have to stay level-headed and save your strength.No one knows how long this will all last," he told AFP.
The intensification of Russian strikes on Ukraine, particularly energy facilities, came after the bridge linking the annexed Crimea peninsula to mainland Russia was partially destroyed by an explosion earlier this month.
It was another major setback for Moscow's forces, battling to contain a Ukrainian counter-offensive in the south and east of the country.
French President Emmanuel Macron said Sunday that it was for Ukrainians to decide when "peace is possible", in comments made in Rome at the start of a peace summit.
Ukraine reported three deaths in an overnight Russian artillery strike in the Toretsk area, a governor of the eastern Donetsk region said.
Inside Russia, two lines of defence have been built in the border region of Kursk to deal with any possible attack, a local governor said on Sunday.
On Saturday Vyacheslav Gladkov, the governor in the neighbouring Russian border region of Belgorod, said the construction of defence structures had begun.
Gladkov said two civilians had been killed in strikes there Saturday, and that 15,000 people had been left without electricity.
Kherson evacuations
Meanwhile Ukraine's SBU intelligence service said it had detained two officials of Ukrainian aircraft engine maker Motor Sich on suspicion of working with Russia.
The SBU said management at the company's plant in Ukraine's southern Zaporizhzhia region -- partly controlled by Russian forces -- had colluded with Russian state-owned defence conglomerate Rostec.
The suspects had supplied Russia with Ukrainian aircraft engines that were used to make and repair attack helicopters, the SBU said.
In the southern Ukrainian region of Kherson, which Russia claims to have annexed, pro-Moscow officials on Saturday urged residents to leave "immediately" amid a "tense situation" at the front.
Kherson, the region's main city, was the first to fall to Moscow's troops and retaking it would be a major prize in Ukraine's counter-offensive.
A Moscow-installed official in Kherson, Kirill Stremousov, told Russian news agency Interfax on Saturday that around 25,000 people had left Kherson city to the left bank of the Dnipro River.
Ukraine has denounced the removal of residents from Kherson, describing them as "deportations".
