Moscow (AFP) - The Kremlin said Thursday that the Moscow-annexed Crimean Peninsula was vulnerable to Ukrainian attacks after officials said they had shot down a drone near a key naval base.

The latest drone attack came after Russian President Vladimir Putin recently visited the only bridge connecting Crimea with the Russian mainland to survey repair work on the key artery damaged in a blast Moscow blamed on Kyiv.

“There are certainly risks because the Ukrainian side continues its policy of organising terrorist attacks,” Kremlin spokesman Dmitry Peskov told reporters.

“But, on the other hand, information we get indicates that effective countermeasures are being taken.”

The Moscow-appointed governor of Crimea Sergei Aksyonov said last month that Russia was strengthening fortifications on the peninsula in the wake of recent attacks.

The governors of two Russian regions bordering Ukraine this week said they had inspected defence lines being built, days after Ukrainian drones struck key military airfields.

In the latest incident over Crimea Thursday, Russia said it had shot down a drone over the Black Sea near Sevastopol, the largest city on the Crimean peninsula, which hosts a key Russian naval base.

“As per usual our military carried out its work well,” said the governor of the Sevastopol administrative region, Mikhail Razvozhayev.

The peninsula was annexed by Russia in 2014 after a controversial referendum that Ukraine and the West never recognised.

Moscow used Crimea as one of its launching pads for its military intervention in Ukraine on February 24 and it has been regularly attacked by drones.

- ‘Spies’ detained -

There have been several explosions at or near Russian military installations in Crimea since February, including a coordinated drone attack on a key Russian naval port at Sevastopol.

In October, the Kerch bridge linking the peninsula to the Russian mainland was partially destroyed, an attack Moscow blamed on Ukraine.

The shooting down of the drone Thursday came after a series of attacks deep inside Russia – one on the Engels airfield, a strategic bomber military base. Ukraine has not claimed responsibility for the attacks.

Separately, the Russian security services (FSB) arrested two people accused of spying for Ukraine on Crimea, accusing them of “treason”, the agency’s press service said Thursday.

The FSB “halted the illegal activities of two Russian citizens suspected of committing high treason in the form of spying in the interests of the Security Service of Ukraine,” it said in a statement.

One of those detained is “a supporter of Ukrainian nationalist ideology and was recruited by the Ukrainian secret services in 2016”, the statement said.

He is suspected of “transferring data on the location of Russia’s defence ministry facilities to a foreign security agency, which could be used against Russia’s security”.

- ‘Significant’ power deficit -

In moves similar to the controversial 2014 Crimean referendum, Russia in September announced it had annexed four Ukrainian regions – Donetsk, Lugansk, Zaporizhzhia and Kherson – even if it never fully controlled them.

Following a series of humiliating defeats, including a retreat from Kherson, the only regional capital it held, Russia began bombarding Ukraine’s energy grid.

On Thursday, the country’s energy system was still struggling with a “significant deficit of electricity”, Ukrainian energy operator Ukrenergo said.

“The situation is complicated by weather conditions: in many regions in the west of the country, frost, rain with snow and strong gusts of wind cause icing of wires and their damage,” the company said.

Putin vowed Thursday to continue attacking Ukrainian energy systems despite global criticism of strikes that have left millions without electricity and water as winter approaches.

And the Kremlin said Time magazine’s decision a day earlier to name Ukraine President Volodymyr Zelensky as “Person of the Year” reflected “Russophobic” trends in Western countries.

The Politico news website also named Zelensky as the “Most Influential” person in Europe.

And during a ceremony in Rome Thursday, Pope Francis was briefly reduced to tears as he prayed for the people of Ukraine.

He had to pause for a moment, his body shaking with emotion, before he could finish his prayer. The crowd around him broke into applause.

In an interview published at the end of November in the US Jesuit magazine America, the pope denounced the “cruelty” of Russia’s troops in Ukraine, drawing a formal protest from Moscow.