Ukraine rebels hold referendums in Donetsk and Luhansk
Pro-Russian separatists in Ukraine's two eastern regions are holding "self-rule" referendums - a move condemned by Ukraine's government and the West.
BBC correspondents at polling stations report chaotic scenes, no voting booths in places and no electoral register.
Self-proclaimed leaders in Donetsk and Luhansk regions are going ahead with the vote despite Russian President Vladimir Putin's call to postpone it.
Ukraine condemned the vote as a "criminal farce" organised by Russia.
An official in Kiev, national security chief Andriy Parubiy, said: "We do not consider there to have been a referendum."
At the scene
At the Primorsky polling station in Mariupol, a large crowd is gathered outside, waiting to vote. There is a crush of people inside.
Organisation is chaotic at best. There are no polling booths: people vote at the registration desks. People's details are hastily scribbled on generic forms. There is also a collection for money towards funding the Donetsk People's Republic.
The chairman of this polling station, Sergei Babin, said that people from other regions are permitted to vote here. He said their details would be taken down, and then, to ensure they haven't voted elsewhere, "the lists from different polling stations would be checked against each other".
Asked how long such a mammoth task would take, he replied "one day."
Ballot papers, in Ukrainian and Russian, ask one question: "Do you support the Act of State Self-rule of the Donetsk People's Republic/Luhansk People's Republic?"
Outbreaks of violence have continued; fighting was reported overnight around rebel-held Sloviansk.
'Total collapse'
Across eastern Ukraine:
- An official at a Sloviansk polling station told the BBC voting was going well. Pro-Russia militiamen in fatigues and balaclavas are voting alongside grandmothers
- But one pro-Ukrainian head teacher said she received death threats after refusing to let rebels use her school as a polling station
- In Donetsk, the BBC's Piers Schofield says the process appears haphazard. Although there are voters' lists in polling stations, one can vote at any station
- BBC reporters say only a handful of polling stations are serving Mariupol, a city of half a million.
A second round of voting is planned in a week's time, on joining Russia. Organisers also say they will boycott Ukraine's presidential elections on 25 May.
Ukraine's interim President Olexandr Turchynov has admitted many in the east supported pro-Russian militants, but warned the referendums were "a step towards the abyss".
East Ukraine referendum
- Voting in separatist-controlled cities and towns of Donetsk and Luhansk
- Some 3,000,000 ballot papers ask: "Do you support the Act of State Self-rule of the Donetsk People's Republic?"
- Second round on joining Russia planned for 18 May
- Vote deemed illegal by Kiev government and international community
The EU and US have also condemned the referendums, amid fears Ukraine could be sliding to civil war.
A Pew Research Centre survey suggested a majority even in eastern Ukraine - 70% - wanted to remain in a united country, despite concerns about governance.
Russia annexed Ukraine's southern autonomous republic of Crimea, after a March referendum.
Bill Taylor, a former US ambassador to Ukraine, said results from Sunday's vote should be treated with caution after what happened in Crimea.
Russia is estimated to have some 40,000 troops near the border and says they have been pulled back, but Nato says it has seen no sign of this.
EU leaders have warned Russia it faces further sanctions if Ukraine's presidential election fails to go ahead.