Russia's defence ministry has said a Russian Su-35 fighter jet was scrambled over the Baltic Sea after two US strategic bombers flew in the direction of the Russian border, but that it returned to base after they moved away.
The development followed the March 14 crash of a US drone into the Black Sea after it was intercepted by Russian jets in what was the first known direct military encounter between Russia and the United States since Russia invaded Ukraine in February last year.
"On March 20, radar facilities of the air defence forces of the Western military district on duty over the Baltic Sea detected two air targets flying in the direction of the Russian Federation's state border," the ministry said on the Telegram messaging app.
It said the targets were US Air Force B52H strategic bombers.
It said a Su-35 fighter jet took to the air in order to prevent a border violation, and added, "after the foreign military aircraft moved away from the Russian Federation state border, the Russian fighter returned to its base airfield."
The ministry said the Su-35's flight was strictly in line with international rules of the use of airspace.
"No violation of the state border of the Russian Federation was permitted," it said.
Russian cruise missiles blown up in transit
Meanwhile, Ukraine's defence ministry said on Monday that an explosion in Dzhankoi, in the north of the Crimean peninsula, destroyed Russian cruise missiles intended for use by Russia's Black Sea fleet.
"An explosion in Dzhankoi city in the north of temporarily occupied Crimea destroyed Russian Kalibr-KN cruise missiles as they were being transported by rail," the ministry's main intelligence directorate said in social media posts.
It said the missiles, designed to be launched from surface ships of Russia's Black Sea fleet, had an operational range of more than 2,500 kilometres on land and 375 kilometres at sea.
Ihor Ivin, the Russian-installed head of the Dzhankoi administration, was quoted as saying the city had come under attack from drones and a 33-year-old man suffered a shrapnel injury from a downed drone.
He was hospitalised and is expected to survive.
TASS quoted Mr Ivin as saying on Krym-24 TV that a house, school and grocery store caught fire, and the power grid sustained damage.
Ukraine says Avdiivka could become 'second Bakhmut'
Ukraine said on Monday the eastern town of Avdiivka could soon become a "second Bakhmut", a small city where its forces have held out against Russian invaders for eight months but risk being fully encircled.
The battle for Bakhmut, in the industrial Donbas, has been one of the fiercest of the nearly 13-month war in Ukraine, drawing comparisons with World War One trench warfare.
The commander of Ukraine's ground forces said last week Moscow's forces were now trying to fully encircle Bakhmut in an offensive that has made no major breakthroughs.
On Monday, the spokesperson for Ukraine's Tavria military command said he agreed with an assessment by British Defence Intelligence that Russia was mounting pressure on supply lines to Avdiivka, as it has done around Bakhmut.
"The enemy is constantly trying to encircle the town of Avdiivka. I very much agree with my colleagues from the UK that Avdiivka may soon become the second Bakhmut," spokesman Oleksiy Dmytrashkivskyi said.
"However, I would like to say that all is not well with the Russian units attacking in this direction."
Ukraine has said Russian forces are taking heavy losses in their offensive in eastern Ukraine.
Avdiivka had a peacetime population of more than 30,000. Unlike Bakhmut, it has been a frontline town for many years.
Ukrainian forces were dug in there long before Russia's full-scale invasion last year, holding the line against Russian-backed militants who took control of swathes of territory in east Ukraine in 2014 after Russian forces seized Crimea.
Avdiivka lies just to the north of the Russian-held city of Donetsk, of which Ukraine lost control in 2014.
British Defence Intelligence tweeted on Monday that Russian forces had made "creeping gains" around Avdiivka and said the sprawling Avdiivka Coke Plant was "likely to be seen as particularly defendable key terrain as the battle progresses".
ABC/wires
