Millions of Kurds have voted for independence from Iraq in a controversial referendum that united neighbouring countries and the wider world – except Israel – in vehement opposition.

More than three million people cast ballots in Monday’s vote covering the Kurdistan region and other territories that the authorities dispute for control with Iraq’s central government Baghdad, such as the oil-rich town of Kirkuk.

Other ethnic groups including Arabs and Turkmens called for boycotts, while neighbours Turkey and Iran mobilised forces close to their borders with the Kurdistan region in a show of force.

“We consider the referendum, regardless of outcome, null and void. We say it is illegal,” Turkish President Recep Tayyip Erdogan said in a speech in Istanbul on Monday.

But Israel has gone against the grain of international condemnation of the referendum, diverging even from the United States’s opposition. Prime Minister Benjamin Netanyahu has offered explicit support for what he called “the legitimate efforts of the Kurdish people to achieve their own state.”

Most voters — 92.73%, according to provisional figures — suported secession, but officials said a declaration of independence was not imminent.

“It is the beginning of a struggle today in which we hope after a talking process with Iraq, with our neighbours, friends and rivals, to be able to reach our nation's objectives, be able to fulfill the dream that grew with us since childhood,” said Qubad Talabani, the deputy prime minister of the Kurdistan Regional Government.

Local news outlet Rudaw announced turnout was 72.16%, with early results pointing to an overwhelming vote in favour of independence.

Analysts believe Israel has much to gain strategically from Kurdish independence and would particularly find comfort in having a militarily effective ally bordering Iran that would diminish Tehran’s influence over Iraq.