BAGHDAD, Iraq — Iraqi voters have ratified a new constitution by a margin of nearly 4 to 1, election officials announced yesterday as complete returns showed that the country’s disaffected Sunni Arab minority had narrowly failed to muster enough “no” votes in three provinces to block the charter’s adoption.

The result, declared 10 days after a nationwide referendum, raised cries of protest from some Sunni leaders, who had claimed that the count was being rigged. But Iraqi election officials and U.N. monitors said a selective recount turned up no significant incidents of fraud.

Shiite Muslim and ethnic Kurdish politicians leading Iraq’s coalition government hailed the passage of the American-backed charter, and President Bush declared in Washington that “the Iraqi people have once again proved their determination to build a democracy united against extremism and violence.”

But their message that the new charter would help isolate the Sunni-led insurgency was drowned out by guerrilla attacks, including car bombings that killed at least at least seven people in the usually calm Kurdish city of Sulaymaniyah.

The violence came a day after a triple car-bombing attack on the Palestine Hotel that was one of the most complex and coordinated the insurgents have staged in Baghdad. The Palestine houses many Western journalists, but the 17 people reported killed in the evening bombings were Iraqis — most of them hotel guards and passersby.

Iraqi Prime Minister Ibrahim al-Jaafari said the attack Monday night and those yesterday were timed for the announcement of voting results and meant to signal the insurgents’ rejection of the new constitution.

Iraq has been run since June 2004 by two successive transitional governments under an interim constitution drafted in part by American and British officials. The new, Iraqi-drafted charter calls for the December 15 election of a National Assembly that will sit for four years and appoint a government that American officials and many Iraqis hope can confront the insurgency more effectively.

Sunnis, who make up about one-fifth of the country’s 27 million people, voted overwhelmingly against the charter. Their leaders fear that the loose federal structure it enshrines will give rise to strong, oil-rich mini-states in the Kurdish north and predominately Shiite south, making permanent the Sunnis’ loss of power since the end of Saddam Hussein’s Sunni-led regime.

Returns made public yesterday by the Independent Electoral Commission of Iraq underscored the country’s sharp division along ethnic and sectarian lines.

Under the electoral law, a two-thirds “no” vote in three or more provinces would have doomed the proposed charter. The next parliament would have been limited to a one-year term and given a mandate to start over.