Russia launched referendums on Friday across four occupied Ukrainian regions in controversial elections that have been widely condemned by the international community.
Locals in Donetsk, Luhansk, Kherson and Zaporizhzhia are being threatened if they refuse to take part in the ballot to join the Russian Federation, reports have stated.
Footage posted on social media shows armed groups of militia going door to door asking people to vote.
Voting in the four provinces, which make up about 15 per cent of Ukrainian territory, is due to run until Tuesday.
Serhiy Gaidai, governor of Luhansk, said in the town of Starobilsk, Russian authorities banned the population from leaving the city until Tuesday.
Yuriy Sobolevsky, the displaced deputy chairman of Kherson region council, said: “The best thing for the people of Kherson would be not to open their doors.”
In Zaporizhzhia, residents also reported being made to vote after armed soldiers arrived at their homes.
The referendums have been condemned by Ukraine and the West as illegitimate and choreographed.
The Organisation for Security and Cooperation in Europe said the outcomes would have no bearing as they do not conform with Ukraine law.
Former Russian president Dmitry Medvedev warned Moscow would deem any attack on the four territories as aggression against Russia itself.
He warned: “Encroachment on to Russian territory is a crime which allows you to use all the forces of self-defence.”
