Iraq was forced to delay the announcement of results from its referendum on a new constitution after the country"s electoral commission said it was rechecking ballots.

The news came amid reports from the restive western city of Ramadi that US air strikes in the western Sunni-dominated Al-Anbar province Sunday had killed several civilians, including children.

As workers tallied votes in Baghdad, the Independent Electoral Commission of Iraq said it "needs several more days to complete this difficult and complex operation after finding that the figures from most provinces were too high," in an apparent reference to turnout levels.

"This will require re-examination, comparison and verification because they are relatively high compared with international averages for elections," a statement said.

"The commission will only announce results when they have been verified."

The delay came after the commission said six majority Shiite provinces in southern Iraq had voted by more than 90 percent in favor of the constitution, while two Sunni-dominated provinces appeared to have rejected the text, by 80 percent in Salaheddin and by 54 percent in Diyala.

The ballots were cast just days before former dictator Saddam Hussein was to stand trial on the first of what could be several cases of crimes against humanity.

Officials estimated that more than half of Iraq"s 15.5 million registered voters had cast ballots in the essentially peaceful referendum on Saturday.

Iraq"s majority Shiite community and minority Kurds strongly support the constitution, while minority Sunnis who were favored during Saddam"s regime generally oppose it.

Last-minute changes were made to the document to persuade Sunni voters to give their approval, including provisions for further amendments by lawmakers to be elected in mid-December elections.

Abdul Hussein al-Hindawi, a senior member of Iraq"s Independent Election Commission, said he was unhappy with early reports of a "yes" victory.

"We are trying to remain cool. Our credibility depends on it," he told AFP.

Hindawi said he had been "surprised" by US Secretary of State Condoleezza Rice"s brief forecast Sunday of voters" approval, saying: "As far as I know, she"s not a member of the electoral commission."

But a source close to the electoral commission acknowledged that it seemed "very difficult" for the "no" vote to win.

The constitution requires a simple majority to be approved but could be defeated if two-thirds of voters in three of Iraq"s 18 provinces reject it.

There are majority Sunni populations in four provinces -- Al-Anbar, Diyala, Nineveh and Salaheddin -- and all reported strong voter turnout.

Media reports of a "yes" victory in Nineveh, which includes the restive mixed city of Mosul were refuted by regional electoral head Dhaher Habib al-Juburi, who said: "There is no truth to these reports," and stressed it would take days for the ballots to be properly counted.

Two Sunni-dominated provinces had rejected the text, central commission spokesman Farid Ayyar, citing provisional figures of 80 percent in Salaheddin and 54 percent in Diyala.

Results from the two other Sunni-dominated provinces, Al-Anbar and Nineveh, were therefore crucial.

"The general trend in Al-Anbar is "no,"" said Adel al-Lami, president of the commission, without giving further details.

Pale neon lighting illuminated election workers in Baghdad as they opened clear plastic boxes containing vote tallies brought in from around the country.

Wearing white T-shirts and baseball caps bearing the electoral commission logo, workers emptied the contents onto long wooden tables, before the data was entered by batteries of computer operators.

"We trust in the ballot boxes," electoral commission officer Aida Salah said. "If it"s no, it"s no, if it"s yes, it"s yes."

Iraq"s neighbors Jordan and Iran congratulated Baghdad on the vote, with Amman saying the large turnout was "extremely favorable" no matter what the result, and Tehran adding that Iraq faced the promise of a "bright future with peace and stability".

British Foreign Secretary Jack Straw and Javier Solana, the EU"s High Representative for Common Foreign and Security Policy said in a joint statement: "This is another historic step for the Iraqi people."

A reminder of what Iraqis went through under Saddam came in the Kurdish city of Arbil, where the remains of 512 members of the Barzani tribe believed massacred by Saddam"s regime were flown back from a mass grave found near the Saudi border in southern Iraq.

On Sunday, US helicopters and combat jets killed around 88 rebels, mainly in air strikes in Al-Anbar, the US military said.

But television reports and a hospital source in Ramadi said some of the victims were civilians.

In Baghdad and northern Iraq, 16 people were killed late Sunday and early Monday, including three Iraqi soldiers and a Christian woman who was shot dead after men forced their way into her apartment, security sources said.

About four percent of Iraq"s overwhelmingly Muslim population is Christian.

The worst incident was in Mosul, capital of Nineveh province, where the bullet-riddled bodies of eight soldiers were found, a police source said.