ERBIL/SULAIMANIYA, Iraq (Reuters) – Voting began in northern Iraq on Monday in an independence referendum organized by Kurdish authorities, ignoring pressure from Baghdad, threats from neighboring Turkey and Iran, and international warnings it may ignite yet more regional conflict.

The vote, expected to deliver a comfortable “yes” for independence, is not binding. However, it is designed to give Massoud Barzani, who heads the Kurdistan Regional Government (KRG), a mandate to negotiate the secession of the oil producing region with Baghdad and neighboring states.

For Iraqi Kurds – the largest ethnic group left stateless when the Ottoman empire collapsed a century ago – the referendum offers a historic opportunity despite the intense international pressure to call it off.

“We have seen worse, we have seen injustice, killings and blockades,” said Talat, waiting to cast a vote in the regional capital of Erbil, as group of smiling women, in traditional colorful Kurdish dress, emerged from the school showing their fingers stained with ink, a sign that they voted.

The Kurds also say the vote acknowledges their crucial contribution in confronting Islamic State after it overwhelmed the Iraqi army in 2014 and seized control of a third of Iraq.