Voting began on Friday in controversial referendums in four Ukrainian regions.

Voting will run from Friday to Tuesday in Luhansk, Donetsk, Kherson and Zaporizhzhia, with people asked to decide if they want these regions to become part of Russia.

Polls will be open from 8 a.m. (0500GMT) to 4 p.m. (1300GMT) in Luhansk, Zaporizhzhia and Kherson, while the closing time will be 8 p.m. (1700GMT) in Donetsk.

For security reasons, in-person voting will only take place on the last day, Sept. 27, while the other days will see ballots being organized in communities and conducted door-to-door, according to local media reports.

Separatist-controlled Luhansk and Donetsk, as well as Kherson and Zaporizhzhia, which are partly under Russian control, announced plans for the referendums earlier this week.

The decision has been widely condemned by the international community, with European states and the US terming them “sham” referendums and saying they will not be recognized.