LONDON, Sept 27 (Reuters) - Russian-installed officials in occupied regions of Ukraine reported huge majorities on Tuesday in favour of becoming part of Russia after five days of voting in so-called referendums that Kyiv and the West denounced as a sham.

Hastily arranged votes had taken place in four areas - the eastern regions of Donetsk and Luhansk, and to the south Zaporizhzhia and Kherson - that make up about 15% of Ukrainian territory.

Luhansk authorities said 98.4% of people there had voted to join Russia. In Zaporizhzhia, a Russian-appointed official put the figure at 93.1%. In Kherson, the head of the voting committee put the "yes" vote at above 87%.

Denis Pushilin, head of the self-proclaimed Donetsk People's Republic, said 99.2% of participants in the region had voted to join Russia. All four areas said all ballots had been counted.

Within the occupied territories, Russian-installed officials took ballot boxes from house to house in what Ukraine and the West said was an illegitimate, coercive exercise to create a legal pretext for Russia to annex the four regions.

Russian President Vladimir Putin could then portray any Ukrainian attempt to recapture them as an attack on Russia itself. He said last week he was willing to use nuclear weapons to defend the "territorial integrity" of Russia.

Putin ally Dmitry Medvedev, a former president who serves as deputy chairman of Russia's Security Council, posted a brief celebratory message on Telegram. "The referendums are over," he said. "The results are clear. Welcome home, to Russia!"

Displaced people from the four regions were able to cast votes in Russia, where state news agency RIA said early counts showed numbers in excess of 96% in favour of coming under Moscow's rule.