The first trains with Russian servicemen from the Union State regional group of forces have arrived in Belarus, the Belarusian Defene Ministry's press service has said on Telegram.
"The decision to create a regional group of troops was made and is being implemented solely in the interests of strengthening the protection of the state border of the Union State on the territory of Belarus and is dictated by the continuous activity in the border areas with us," the ministry said.
On 4 October, Alyaksandr Lukashenka confirmed Belarus's participation in the war against Ukraine on the side of Russia.
On 10 October, it became known that Lukashenka and Russian President Vladimir Putin agreed to deploy a "joint regional group of troops".
After that, President Volodymyr Zelenskyy invited the Group of Seven (G7) countries to deploy an international observation mission on the Ukrainian-Belarusian border to refute the Russian provocation and fakes about Ukraine's alleged plans to start military action against Belarus.
On 13 October, it was reported that Russian military were being brought to Belarusian training grounds. Echelons were spotted being formed at the Ilyino station in Russia's Nizhniy Novgorod Region.
On 13 October, the regime of counter-terrorist operation was introduced in Belarus.