BAGHDAD (Reuters) - Iraqi officials checking results from some regions in Saturday"s constitutional referendum said on Tuesday the audit did not imply fraud in the voting.

Iraq"s Electoral Commission said on Monday it would follow international practice by examining "unusually high" results from provinces which recorded margins of 90 percent or more in favor or against the new draft constitution.

The statement fueled debate over the bitterly fought referendum, with some Sunni Arab leaders suggesting the Shi"ite- and Kurdish-led government had fiddled with numbers to ensure passage of the U.S.-backed charter.

But Commission member Farid Ayar said on Tuesday that lopsided turnouts were not unexpected in Iraq, where historic sectarian divisions have been exacerbated by months of bloody ethnic and communal violence, polarizing local results.

"It"s not surprising where you have 95 percent, for example, in Najaf ... but we have to check," Ayar told Reuters, referring a mainly Shi"ite southern province.

"If there is any result over 90 percent it is better to investigate those again. We are reviewing all the numbers, yes and no."

Partial results indicate a solid win for the constitution, despite fierce opposition among minority Sunni Arabs who fear it will seal their political eclipse in a country they once dominated under Saddam Hussein.

A two-thirds "No" vote in three of Iraq"s 18 provinces would block the charter. But it appeared that only two provinces had voted "No" by that margin, making the chances of a veto remote.

Election officials say the final tally may be days away, but privately say the constitution probably passed in a referendum that was largely peaceful despite widespread fears of violence.

REGIONAL DVISIONS

Early results showed big regional splits. Shi"ite-dominated southern provinces, including Najaf and Kerbala, saw support for the constitution at 85-95 percent, while the heavily Kurdish province of Sulaimaniya reported a 98-percent "Yes" vote.

Provinces in the Sunni heartlands of central Iraq rejected the charter, with Salahaddin -- Saddam"s home province -- returning a 70-percent "No" vote and the restive city of Falluja in Anbar province reporting 99 percent of voters voting "No."

But the northern province of Nineveh around the city of Mosul, seen as the Sunnis" best hope for a third "No," fell well short of the required two-thirds majority, a senior Iraqi official said.

Iraqi non-governmental groups who monitored the vote said they had observed some violations at polls in Shi"ite, Sunni and Kurdish areas but nothing that would affect the overall result.

"There were some violations in more than one polling station in the (Sunni-dominated city of) Samarra, where we noticed voting sheets with more than the actual number of voters who participated," said Maad al-Jibouri of the Iraqi Organization for Free Elections.

Jibouri said the results in Nineveh, under scrutiny amid Sunni charges, denied by Kurds, that Kurds packed the province with voters to defeat the "No" vote, were also problematic.

Referendum observers also reported some problems in Baghdad, where the volatile communal mix made results hard to predict.

Abdul Rahman al-Mashhadani, head of the Hamourabi Human Rights Organization, said the recent agreement by Shi"ite and Kurdish leaders to consider amendments to the constitution to appease Sunni groups may have helped reduce the "No" vote.

"I think there will be some kind of political deal to finalize a "Yes" majority, with agreements and compromises among the political groups," he said.

The Electoral Commission said it was examining all alleged irregularities and would not rush to declare the final tally.

"We are reviewing all of the numbers that we have received which are statistically unusual. We will investigate all complaints fully. This is a normal procedure for ensuring a fair and transparent election," a Commission statement said.