The Conquest (Fatah) Alliance, the political arm of the multi-party Hashed, won around 15 of 329 seats contested in the October 10 vote, according to preliminary results.

In the last parliament it held 48, making it the second-largest bloc.

The big winner this time, with more than 70 seats according to the initial count, was the movement of Moqtada Sadr, a Shiite Muslim preacher who campaigned as a nationalist and critic of Iran.

But the numerous political parties will engage in lengthy negotiations to form alliances and name a new prime minister.

An AFP correspondent said several hundred Hashed supporters gathered on a Baghdad street leading to an entrance to the Green Zone, which is home to the US and other embassies, as well as Iraq's electoral commission and government offices.

"No to fraud, no to America," they chanted.

The Hashed demands the withdrawal of US forces from the country.

Protesters later began setting up tents for the sit-in.

"The results that were announced were rigged," said Ahmed Salman, a 23-year-old day labourer, helping to put up a tent.

"We'll stay here until they give back the votes they stole from us."

Another protester, a 25-year-old man wearing a black Covid mask and sunglasses, said: "The objective of the fraud is clear... it is the dissolution of the Hashed." He declined to be identified.

Hashed supporters have organised sporadic protests across the country for several days.

On Sunday, they burnt tyres and blocked roads south and north of Baghdad.

Activists accuse the Hashed's armed forces -- whose 160,000 fighters are now integrated into Iraq's state security forces -- of being beholden to Iran and acting as an instrument of oppression against critics.

Hashed leaders have rejected the results as a "scam" and said they will appeal, ahead of a final tally expected in the next few weeks.

On Saturday a coalition of Shiite parties, to which the Hashed belongs, toughened their tone, accusing the electoral commission of not correcting "major violations" in the vote counting, and blaming it for "the failure of the electoral process".

They warned of negative repercussions on democracy.

The Hashed is still expected to carry weight in parliament through the co-optation of independent candidates and other alliances.