Results seen as foregone conclusion in favour of annexation, and Ukraine and its allies have made clear they will not recognise the votes
Residents of four areas of Ukraine controlled by pro-Moscow forces have started voting in referendums on joining Russia, polls widely condemned by the west as illegitimate and a precursor to illegal annexation.
Voting in the Luhansk, Donetsk, Kherson and Zaporizhzhia provinces, representing about 15% of Ukrainian territory, began on Friday morning, according to Russian news agency Tass, and was due to run until Tuesday.