Word of the review came as Sunni Arab leaders repeated accusations of fraud after initial reports from the provinces suggested the constitution had passed. Among their allegations were that police took ballot boxes from heavily "no" districts, some "yes" areas had more votes than registered voters and that supporters of the charter were allowed to vote in crucial provinces where they don't live.
CBS News correspondent Allen Pizzey reports that initial results had almost no turnout in some Sunni areas and as high as 66 percent in others,
The Electoral Commission, announcing the audit, made no mention of fraud, and an official with knowledge of the election process cautioned that it was too early to say whether the unusual numbers were actually incorrect or whether they would have an effect on the outcome.
But questions over the numbers raise tensions over Saturday's referendum, which has already sharply divided Iraqis. Most of the Shiite majority and Kurds — who control the government — support the charter, while Sunni Arabs sharply opposed a document they fear will tear Iraq apart and leave them weak and out of power.
Pizzey reports that the high turnout in many Sunni areas was a slap in the face to insurgents who had called for a boycott of the referendum and threatened to kill anyone who voted.
Irregularities in Shiite and Kurdish areas, expected to vote strongly "yes," may not affect the final outcome. The main electoral battlegrounds were provinces with mixed populations, two of which went strongly "yes." There were conflicting reports whether those two provinces were among those with questionable figures.
In new violence, the U.S. military said that its warplanes and helicopters bombed two western villages Sunday, killing an estimated 70 militants near a site where five American soldiers died in a roadside blast. Residents said at least 39 of the dead were civilians.
A sandstorm also became a factor in the vote count, preventing many tallies from being flown from the provinces to Baghdad, where they are to be compiled and checked. The electoral commission said it needed "a few more days" to produce final results, citing the need for the audit.
At Baghdad's counting center, elections workers cut open transparent and sealed plastic bags full of tally sheets sent from stations in the capital and its surroundings — the only ones to have arrived so far. Nearby, more workers, dressed in white T-shirts and caps bearing the elections commission's slogan, sat behind computer screens punching in the numbers.
Election officials in many provinces have released their initial counts, indicating that Sunni attempts to defeat the charter failed and that it was adopted.
But the Electoral Commission found that the number of "yes" votes in most provinces appeared "unusually high" and would be audited, with random samples taken from ballot boxes to test them, the commission's head, Adil al-Lami said.
The high numbers were seen among the nine Shiite provinces of the south and the three Kurdish ones in the north, Adil al-Lami, head of the commission, told The Associated Press.
Those provinces reported to AP "yes" votes above 90 percent, with some as high as 97 and 98 percent.