Monday's vote was the first held in a decade and took place amid widespread political apathy in the oil-rich country, which is recovering from years of conflict and plagued by corruption.

The vote in 15 of the country's 18 provinces is seen as a key test for Prime Minister Mohammed Shia al-Sudani, who rose to power just over a year ago, backed by pro-Tehran parties.

It precedes a general election due in 2025, but experts predict it will strengthen the dominance of the pro-Iran groups in Iraq.

The electoral commission announced the preliminary results at a news conference during which officials gave the number of votes secured in each province by each political group.

In nine provinces of southern and central Iraq, the winners were mostly from pro-Iran groups that dominate parliament or from formations aligned with outgoing governors.

Vying for victory were the "Nabni" (We build) alliance led by Hadi al-Ameri, a senior commander of the Hashed al-Shaabi, a network of former paramilitary units now integrated into the regular forces.

Other pro-Iran groups that appeared headed to win in southern and central Iraq were former prime minister Nuri al-Malki's State of Law coalition, closely followed by the Patriotic forces of the State Coalition, led Shiite cleric Ammar al-Hakim and ex-premier Haider al-Abadi.

In the capital Baghdad, however, the Taqadom party of Sunni Muslim speaker of parliament Mohamed al-Halbussi came first, although Nabni and State of Law coalitions were close behind.

The provincial councils, set up after the 2003 US-led invasion that toppled dictator Saddam Hussein, choose regional governors and manage budgets for health, transport and education.

Critics see them as hotbeds of corruption and clientelism, and they were abolished in late 2019 after mass anti-government protests before being re-established under Sudani.

The electoral commission said voter turnout was 41 percent, almost 6.6 million voters out an electorate of more than 16 million.