Russia conducted naval drills in the Barents Sea in August to prevent unauthorised and foreign ships from passing, its Interfax news agency said on Saturday.
The destroyer Vice-Admiral Kulakov “practised a case to repel the actions of a mock intruder vessel” in the Arctic Ocean off the northern coasts of Norway and Russia, Interfax said.
The drills by Russia's Northern Fleet began on August 10, the agency said without giving an end date.
The fleet is planning more exercises to “defend Russia's insular and continental territories in the Arctic”, as well as to ensure the safety of maritime navigation and other Russian maritime economic activities in the Arctic zone, Interfax said.
Late on Saturday morning, Russia's Defence Ministry said it had destroyed a drone over the Belgorod region, which borders Ukraine and regularly comes under fire.
Also on Saturday, Russia said that it shot down two drones over its Belgorod region and one headed for Moscow, as it reported Ukrainian shelling wounded six people in a border town.
Russia and the Moscow-annexed Crimean peninsula have been hit by a wave of attacks in the past month, after Kyiv warned in July it aimed to "return" the conflict to Russian territory.
The Russian defence ministry said one drone was destroyed close to the border in Belgorod region at 9am, while another was intercepted over the region at 2.15pm.
A separate drone headed for Moscow in the early hours of the morning was also thwarted, the defence ministry said.
Moscow, which was rarely attacked during the early stages of the conflict, is now being targeted by almost daily drone strikes.
"Tonight, air defence forces destroyed a drone on approach to Moscow in the Istrinskii district," the capital's mayor Sergei Sobyanin wrote on Telegram.
"Preliminarily, there were no casualties or damage. Emergency services are working on the site," he added.
The drone attacks came as the governor of Russia's Belgorod region said Kyiv shelled the town of Urazovo, about 10 kilometres (six miles) from the Ukrainian border, injuring six people.
Russian regions bordering Ukraine have regularly accused Kyiv's armed forces of indiscriminate shelling and occasional cross-border incursions by Ukrainian-backed militants.
Governor Vyacheslav Gladkov accused Ukraine of firing "cluster munitions" in Saturday's attack, and said residential buildings had been damaged.
"As a result of the cluster munition strike, six civilians sustained shrapnel wounds," he said in a social media update, after initially reporting four had been injured.
"One victim is in extremely serious condition," he wrote on Telegram.
Ukraine rarely claims attacks inside Russia or on Russian-controlled territory in Ukraine, although its military has claimed that destroying Russia's military infrastructure helps a counter-offensive that Kyiv began in June.
In Ukraine, two people were killed and one wounded on Saturday when Russian shelling hit a cafe in the village of Podoly in the eastern region of Kharkiv, local governor Oleh Synehubov said.
“The enemy hit a civilian object – a cafe where local residents were during the day,” Mr Synehubov wrote on Telegram.
Separately, Ukrainian forces say they have broken through the most difficult line of Russian defences in the south and will now be able to advance more quickly, according to a commander fighting in the south.
Ukraine launched a counteroffensive in June, but well-prepared Russian defence lines reinforced by minefields have slowed their southward advance towards the Sea of Azov.
Ukrainian forces said on Wednesday they had raised the national flag in the settlement of Robotyne in the southern Zaporizhzhia region, about 10km south of the frontline town of Orikhiv.
"We don't stop here," said a commander who led some of the troops into Robotyne and who uses the callsign "Skala," eponymous with the battalion which he leads.
"Next we have (the town of) Berdiansk, and then more. I made it clear to my fighters at once: our goal is not Robotyne, our goal is (the Sea of) Azov."
Robotyne is about 100km from Berdiansk, a port on the shores of the Sea of Azov, and 85km from the strategic city of Melitopol. Both are occupied by Russian forces following Moscow's full-scale invasion in February last year.
Moscow has not confirmed that Ukraine has advanced into Robotyne.