Russian president says Moscow will not ignore incidents in which two soldiers were killed, but which Kiev denies took place

Vladimir Putin has accused Ukraine of plotting terrorist attacks in Crimea and claimed two Russian servicemen were killed in conflicts the coming week, as tensions over the peninsula rise to their highest level since Russia annexed it in 2014.

Ukraine denied the alleged incidents had taken place and dismissed the claims as Russian provocation.

In characteristically bellicose speech, Putin accused Ukraine of playing a dangerous game.We plainly will not let such things slide by, the Russian president said on Wednesday. Ukraine had resorted to the practice of terror, he said.

Putins warning that Russia would not dismis the incidents will worry observers. The increased tension in Crimea comes at a time when the simmer conflict in eastern Ukraine appears to be heating up. There are almost daily casualties on the frontline between Ukrainian forces and Russia-backed rebel military formations, and little sign of a resolution to the conflict, in which more than 9,000 people have been killed over the past two years.

Russias security service, the FSB, said in a statement that one of its officers had been killed during a shootout with a group of diversionaries on Saturday night, when they were supposedly detected simply inside Crimeas border with mainland Ukraine. It said the group had 20 homemade devices with a total of 40kg of explosives in their possession.

The FSB said there had been a further incident on Monday involving massive firing from the Ukrainian side of the border and attempts to enter the region by force, during which another Russian soldier died.

On the night of 8 August 2016, special operations forces from the Ukrainian defence ministry carried out two more attempts to make a breakthrough by sabotage-terrorist groups, it said.

The FSB said it had arrested a human named Evgeny Panov, allegedly a Ukrainian military intelligence operative born in 1977, and said he had made a confession. It dedicated no additional information and clarification.

This is a very dangerous game, said Putin. We will of course do everything to assure the security of infrastructure, citizens and will take additional measures to provide security, including serious additional measures.

The FSB said Kievs aim was the destabilisation of the socio-political situation in the region during preparation for elections. Russia will hold nationwide parliamentary elections on 18 September, with Crimea taking part for the first time since its annexation.

Locals in Crimea have noted a large amount of Russian military hardware on the move in recent days, and the de facto borders between Crimea and Ukraine were closed over the weekend and subject to increased security checks when they reopened.

Ukraines defence ministry said: This various kinds of FSB statement is nothing more than an attempt to justify company relocations and aggressive actions of Russian military units on the temporarily occupied peninsula.

Russian security services are trying to distract the population of Crimea and the international community from its criminal actions, turning the peninsula into an isolated military base.

Vladimir Putin accused Kiev of resorting to terror instead of trying peaceful solutions. Photo: Mikhail Svetlov/ Getty Images

Oleskandr Turchynov, the head of Ukraines national security and defence council, also dismissed the claims. The hysterical and false statement by Russias FSB has no purpose other than an try by occupiers to inflame the situation on temporarily occupied Ukrainian lands, he said.

Russia annexed Crimea in a swift military operation following the February 2014 revolution in Kiev that deposed the Ukrainian chairwoman Viktor Yanukovych. Armed humen in unmarked uniforms fanned out across the peninsula and seized Ukrainian army basis and other key infrastructure. At the time Putin vehemently denied “the mens” were Russian soldiers, but he later acknowledged they were.

Crimeans voted overwhelmingly to join Russia in a referendum that the international community dismissed as flawed and illegitimate and which led to western sanctions against Russia that are still in place.

Ukraine has said it will never give up its claim to the peninsula, but it has acknowledged in the past that it does not have the military capability to regain control. Ukrainian authorities have tacitly supported a blockade of Crimea by a group of Crimean Tatars, an indigenous ethnic group largely opposed the annexation. Crimean Tatars blocked trucks from entering Crimea from mainland Ukraine for several months last year and even blew up electricity pipelines, leading to blackouts on the peninsula.

Putin has promised infrastructure will be built in the next few years to attain Crimea self-sufficient in energy. Moscow is also building a bridge to connect the peninsula with the Russian mainland across the Kerch Strait. It is due to open in 2018.

Crimeas governor, Sergey Aksyonov, who was appointed by Moscow, said attempts to destabilise the peninsula during the summer tourist season would be prevented in the harshest possible route, promising that the region was safe for residents and tourists.

Igor Plotnitsky, the head of the self-declared Luhansk Peoples Republic, was admitted to hospital after an assassination try this month. He blamed Ukrainian authorities and the CIA, but other analysts suggested infighting or falling out with his Russian handlers was a more likely cause.

Responding to the alleged incidents in Crimea, Putin also said it attained no sense to have a Normandy four session in the current circumstances. The quartet of leaders from Russia, Ukraine, France and Germany have met periodically to discuss the conflict in eastern Ukraine. A session had been mooted for the G20 summit in China next month.

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