A Russian military transport aircraft carrying eight crew and seven passengers came down in the Ivanovo region north-east of Moscow, in the second such incident this year, the Defence Ministry reported on Tuesday.
There was a huge explosion when the aeroplane hit the ground. Everyone on board the Ilyushin Il-76 died, according to a report citing the ministry carried by the Interfax news agency.
Interfax reported that one of the plane's four engines had caught fire on take-off.
What caused the crash has not been determined. Authorities said a technical cause was suspected. Aviation experts were on their way to inspect the site.
An Il-76 went down in the Belgorod region near the border with Ukraine in January. According to the Russian authorities, the transport plane was hit by a missile fired from the Ukrainian side of the border. They said 65 Ukrainian prisoners-of-war were aboard when it came down.
The Ilyushin aircraft is used to transport troops, goods and military technology. In addition to the seven-person crew, it can transport up to 126 paratroopers with full equipment and a maximum of 48 tons of cargo.
Meanwhile dozens of Ukrainian combat drones attacked targets in several parts of Russia overnight, Russian authorities said on Tuesday, including an oil refinery some 800 kilometres from Ukraine.
Twenty-six drones were intercepted above seven different districts. including in the St Petersburg region, the Defence Ministry in Moscow said.
According to the media, the most distant target was a refinery belonging to the Russian oil company Lukoil in Kstovo near the city of Nizhny Novgorod east of Moscow, where a drone caused a fire. The city on the Volga is located some 800 kilometres from Ukraine.
A railway fire engine was deployed to fight the flames, regional Governor Gleb Nikitin said on Telegram.
A fire also broke out in a petrol depot in the south-western district of Oryol after it was hit by a drone, state news agency TASS reported.
One woman was reported to have been injured. However, it was not possible to independently verify the information from the attacks.
On Tuesday afternoon, a Ukrainian drone damaged the Belgorod city administration, the administrative headquarters of the Belgorod region near the border. According to Governor Vyacheslav Gladkov, two women were slightly injured. Another drone fell onto the roof of a shopping centre near the train station.
Moscow reported that there had been Ukrainian attacks of a similar scale at the weekend.
In recent weeks, Ukraine, which has been fending off a full-scale Russian invasion for more than two years, has increasingly targeted metal factories and oil and gas facilities with combat drones in order to disrupt supplies for the attacking Russian troops.
The range of Ukraine's domestically manufactured weapons has increased in the process. However, the consequences of the attacks are usually not as devastating as the Russian missile and drone attacks on Ukrainian cities.
Russian forces have seized the village of Nevelske to the immediate north-west of the city of Donetsk in eastern Ukraine, the Defence Ministry reported in Moscow.
The ministry claimed that Russian forces had also advanced elsewhere along the front in the Donetsk region.
Air-raid sirens sounded in Kiev on Tuesday for the 1,000th time since the start of the full-scale Russian invasion, the regional military governor, Serhiy Popko, posted on Telegram.
The sirens had sounded for a total of 1,165 hours and 26 minutes in that period, Popko said. "That's more than 48 hours of uninterrupted alerts."
Ukrainians had been living in air-raid shelters for more than a month and a half, he said. But Ukrainians had become inured to the hardship, he added.
The alert in Kiev on the 748th day of the war lasted exactly 17 minutes, according to official information. The Ukrainian air defences usually sound the alert when Russian aircraft or drones take off from their bases in Russia and head for Ukraine.