Iraq's electoral commission said it intended to audit "unusually high" numbers in results coming from most provinces in Saturday's landmark referendum.
The commission's statement came Sunni Arab lawmaker, Meshaan al-Jubouri, on Monday claimed fraud had occurred in the vote - including instances of voting in hotly contested regions by pro-constitution Shiites from other areas - repeating earlier claims of election-fixing made by other Sunni officials over the weekend.
"Statements coming from most govern orates indicating such high numbers that require us to recheck, compare and audit them, as they are unusually high according to the international standards," the Independent Electoral Commission of Iraq said in a statement.
The commission said it would take random samples from ballot boxes from areas reporting "very high percentages or too low percentages in the results."
It did not specify which provinces the unusual reports were coming from, or say whether the unusual numbers could affect the outcome.
Further delaying the count and the posting of final results from Saturday's vote, a sandstorm swept over Baghdad on Monday, grounding air travel into the capital. Vote tallies still have to be flown in from the provinces, and workers at the central counting center in the capital were still only working on results that arrived from Baghdad and its outskirts.
The commission said it would "need a few more days" to reach a final result, particularly given the need to check the unusual numbers.
Figures reported by elections officials in the provinces to The Associated Press indicated that the constitution appeared to have passed, with the Sunni Arab attempt to veto it falling short.
Many Sunnis fear the new decentralized government will deprive them of their fair share of the country's vast oil wealth by creating virtually independent mini-states of Kurds in the north and Shiites in the south, while leaving Sunnis isolated in central and western Iraq.
Opponents failed to secure the necessary two-thirds "no" vote in any three of Iraqi's 18 provinces, according to counts that local officials provided to the AP. In the crucial central provinces with mixed ethnic and religious populations, enough Shiites and Kurds voted to stymie the Sunni bid to reject the constitution.
The Sunni "no" campaign appeared to have made the two-thirds threshold in Anbar province
, the vast western Sunni heartland where Ramadi is the capital, and in Salahuddin, where Sunnis hold a large majority and as many as 90 percent of voters cast ballots. But in two other provinces where Sunni Arabs have only slim majorities - Ninevah
- the "yes" vote apparently won out.
Sunni leaders responded angrily, some of them saying they suspected fraud and accusing American officials and the Shiite parties that dominate the government. While a strong Sunni turnout suggested a desire among many to participate in Iraq's new political system, there were fears that anger at being ruled under a constitution they oppose could push some into supporting the Sunni-led insurgency.
If the constitution indeed passed, the first full-term parliament since Saddam Hussein's fall in 2003 will install a new government by Dec. 31 following Dec. 15 elections. If the charter failed, the parliament will be temporary, tasked with drawing up a new draft constitution.