Russia's defense ministry says its forces repelled Ukrainian offensives in Russian-held areas in the Donetsk region in eastern Ukraine. But Ukrainians accused Russia of disseminating false information.

The Russian ministry said early on Monday that "the adversary launched a large-scale offensive from the morning of June 4 on five sectors of the front in the south Donetsk area" but failed.

The Ukrainian defense ministry accused the Russians of waging an information war.

The commander of Ukraine's ground forces, Oleksandr Syrskyi, wrote on social media on Saturday that enemy troops are suffering significant losses in Bakhmut in Donetsk.

He also said on Monday that Ukrainian forces continue "moving forward" near the strategic city.

Meanwhile, the western Russian region of Belgorod that borders with Ukraine has been under shelling and other forms of attacks since the start of this month.

The local governor said on Monday that a fire broke out at an electric power facility following an apparent drone strike.

Drone attacks are said to be targeting fuel depots and other key facilities in Russian regions near Ukraine.

Analysts say the Ukrainian military is carrying out shaping operations that involve attacks on weapons depots and other logistic bases ahead of counteroffensives, although it remains unknown when they will start.

On Monday, the Russian defense ministry announced that the country's Pacific Fleet began an exercise in the Sea of Japan and the Sea of Okhotsk.

The drill involving more than 60 vessels, about 35 aircraft and more than 11,000 personnel will be held through June 20. The personnel will perform simulations of tracking down enemy submarines, and test-firing missiles against at-sea and mid-air targets.

The drill is believed to be aimed at demonstrating the power of the Russian fleet to the United States and Japan.