Boris Johnson has joined other leaders in describing an alleged attack on a kindergarten in a Russian separatist-held part of Ukraine as a “false flag” operation.
The occupation forces, who Russia provides arms to, are in the Donbas region of Ukraine near the Russian border.
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They have accused Ukrainian government forces of opening fire on their territory – taken from Ukraine in 2014 – four times in the past 24 hours.
However, Kyiv has claimed the rebels fired several shells on the village of Stanitsya Luhanska in the occupied area on Thursday – with some hitting a kindergarten, injuring two civilians and damaging a number of buildings.
British Prime Minister Mr Johnson, speaking at a military base in Lincolnshire, said: “Today, as I’m sure you’ve already picked up, a kindergarten was shelled in what we are taking to be – well, we know – was a false flag operation designed to discredit the Ukrainians, designed to create a pretext, a spurious provocation for Russian action.
“We fear very much that that is the kind of thing we will see more of over the next few days.”
His comments come after NATO secretary general Jens Stoltenberg said: “We are concerned that Russia is trying to stage a pretext for an armed attack against Ukraine, there is still no clarity, no certainty about the Russian intentions.”
And British Foreign Secretary Liz Truss said the alleged shelling is “a blatant attempt by the Russian government to fabricate pretexts for invasion… this is straight out of the Kremlin playbook”.
Ukrainian President Volodymyr Zelenskyy said it was a “big provocation” as he called for all diplomats to remain in Ukraine as their monitoring activities “are an additional deterrent”.
Shelling provokes fears war imminent
Details of the incidents could not be independently confirmed and initial reports suggest they were on a similar scale to ceasefire violations common over the eight-year conflict.
However, as they come at a time when the West is warning Russia is about to invade Ukraine, fears a war is about to start have heightened.
A senior Western official told Sky News an “uptick in violence is common at this time of year”, however some feel it could be a “false flag” to give Russia an excuse to invade.
US President Joe Biden said Washington has “reason to believe that they [Russia] are engaged in a false flag operation to have an excuse to go in”.
He said there is “every indication” that “they’re prepared to go into Ukraine, attack Ukraine” and he believes an invasion will begin within “several days”.
Secretary of state Anthony Blinken echoed this, saying it is the US view that Moscow “plans to manufacture a pretext for its attack”.
“This could be a violent event that Russia will blame on Ukraine, or an outrageous accusation that Russia will level against the Ukrainian government,” he told the UN Security Council.
“We don’t know exactly the form it will take. It could be a fabricated so-called terrorist bombing inside Russia; the invented discovery of a mass grave; a stage drone strike against civilians; or a fake, even a real attack using chemical weapons.
“Russia may describe this event as ethnic cleansing or a genocide, making a mockery of a concept that we in this chamber do not take lightly.”
More: West ‘blinked’ over troop deployment and sanctions will push Russia towards China, senior MP warns
Kremlin says ‘fake reports’ of more troops at border
Russia has said it is pulling back troops from the border, with a Kremlin spokesman on Thursday saying certain phases of drills near Ukraine and in Crimea are nearing their end and those troops will then return to their bases.
The spokesman said it takes “weeks” to deploy forces for military exercises and returning troops back to their bases afterwards “cannot be done in a day”.
He said the Russian defence ministry has a “clear timetable” to withdraw forces after the war games but did not give details.
The Kremlin spokesman also said he hopes people will not believe “fake reports” about a possible Russian invasion date.
US and UK says Russian troops moving towards border
However, the US defence secretary said the US has seen some Russian forces inching closer to the Ukrainian border and they are stocking up on blood.
Speaking at the UN Security Council, Foreign Office minister James Cleverly said Russia is “patently failing to live up to the international commitments that it has made around military transparency”.
He said everyone can see “Russia has deployed the forces necessary to invade Ukraine and now has them readied for action”.
Earlier on Thursday, UK armed forces minister James Heappey told Sky News Kremlin claims troops are moving away from the border are “inaccurate, it’s disinformation”.
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He said NATO intelligence shows more troops are moving towards the border and into formations and positions they could “credibly begin a manoeuvre” from, as well as building field hospitals.
Mr Heappey, who served with the army in Iraq, said there are large concentrations of troops in Crimea and ships in the Black Sea that pose “a real threat” to the key port of Odesa, as well as a large number of troops just to the north of Kyiv.
UK Defence Minister Ben Wallace, ahead of a NATO meeting in Brussels, said: “We have seen the opposite of some of the statements. We have seen an increase of troops over the last 48 hours, up to 7,000.
“We are deadly serious and we’re going to face the threat that is currently being posed.”