KYIV, Dec 26 (Reuters) - Moscow said on Monday its forces had shot down a Ukrainian drone close to a long-range bomber base deep inside Russia, while Ukraine said the Russians had unleashed heavy artillery barrages on its cities in the past 24 hours.
The drone was allegedly flying near Russia's Engels air base, where long-range strategic bombers that may have been used to target Ukrainian cities and infrastructure are based.
The Russian defence ministry said in a statement three air force personnel had been killed in the incident but no planes were damaged.
However, Russian and Ukrainian social media accounts said a number of planes had been destroyed. Reuters was not able to independently verify those reports.
As the war entered its 11th month, Russian President Vladimir Putin said on Sunday he was open to negotiations, and he blamed Ukraine and its Western allies for failing to engage in talks.
But his forces kept up their relentless attacks, with the Ukrainian military saying early on Monday dozens of towns in the Luhansk, Donetsk, Kharkiv, Kherson and Zaporizhzia regions had been shelled.
"In the Kherson direction, the enemy continues artillery shelling of populated areas along the right bank of the Dnipro River," the Ukrainian military said.
Ukrainian forces launched attacks on almost 20 Russian targets, it added.
Ukraine's energy grid operator said power was still significantly lacking on Monday, with emergency restrictions for electricity consumption introduced in five Ukrainian regions and the capital Kyiv.
CRUISE MISSILES
The attack on the Engels air base - located near the city of Saratov, about 730 km (450 miles) southeast of Moscow and hundreds of kilometres from the frontlines in Ukraine - was the second this month.
It was previously hit on Dec. 5 in what Russia said were Ukrainian drone attacks on two Russian air bases that day.
The air base is one of two strategic bomber bases housing Russia's air-delivered nuclear capability. There was no comment from Kyiv, which has never publicly claimed responsibility for attacks inside Russia.
"A Ukrainian unmanned aerial vehicle (drone) was shot down at low altitude while approaching the Engels military airfield in the Saratov region," the defence ministry statement said.
Three Russian servicemen were killed by falling drone wreckage, it said.
Russia has 60 to 70 strategic bomber planes of two types - the Tu-95MS Bear and the Tu-160 Blackjack. Both are capable of carrying nuclear bombs and nuclear-armed cruise missiles as well as conventional munitions.
Moscow has used its air force to fire cruise missiles in attacks that Kyiv has said amount to war crimes.
Saratov's regional governor Roman Busargin said on Monday civilian infrastructure facilities had not been damaged in the latest incident at the base and there was no threat to residents.
Putin on Sunday again said he was open to negotiations - a stance Ukraine's most powerful backer, the United States, has previously dismissed as posturing given the relentless Russian attacks.
"We are ready to negotiate with everyone involved about acceptable solutions, but that is up to them - we are not the ones refusing to negotiate, they are," Putin said in an interview on Rossiya 1 state television.
An adviser to Ukrainian President Volodymyr Zelenskiy said Putin needed to acknowledge it was Russia that did not want talks.
"Russia single-handedly attacked Ukraine and is killing citizens," the adviser, Mykhailo Podolyak, said on Twitter. "Russia doesn't want negotiations, but tries to avoid responsibility."
Russian attacks on Ukraine's power stations have left millions without electricity and Zelenskiy said in an address to the nation that Moscow would aim to make the last days of 2022 dark and difficult.
Russia's defence ministry said on Sunday its forces had killed about 60 Ukrainian servicemen the previous day along the Kupiansk-Lyman line of contact and destroyed numerous pieces of Ukrainian military equipment.
Reuters could not verify the reports.
The Kremlin says it will fight until all its territorial aims are achieved, while Kyiv says it will not rest until every Russian soldier is ejected from the country.