LONDON — Iraq is facing several civil wars between a number of rival communities struggling for power and has “fractured” into regional power bases, a report by an adviser to the British government said.

There are “many civil wars and insurgencies,” and the Middle Eastern country has fractured into “regions dominated by sectarian, ethnic, or tribal political groupings,” said a report released yesterday by Chatham House, a London-based international affairs organization which advises European governments, including Britain.

Iraq’s ethnic and sectarian communities include minority Sunni Muslims, majority Shiites, Kurds, and Turkmen. Some 1,500 civilians were killed in April, the report said, citing official Iraqi statistics. The U.S. military is deploying about 30,000 additional forces to Baghdad and surrounding areas in an attempt to quell rampant violence in the country.

This year will be “a particularly crucial period,” as many of the “most destabilizing issues,” including an oil revenue sharing law, federalism, and the territorial borders of the autonomous Kurdish region in the north of the country, are due to be resolved, said the report, titled “Accepting Realities in Iraq.”

America and Britain, the main military partners in a coalition that invaded Iraq in March 2003, “continue to struggle” in their analysis of the country’s political and social structures, said Gareth Stansfield, author of the report.

“This analytical failing has led to the pursuit of strategies that suit ideal depictions of how Iraq should look, but are often unrepresentative of the current situation,” Mr. Stansfield said in the report.

In Baghdad, Sunni and Shiite groups are fighting for control of the state. There is a “rapidly emerging conflict” between Kurds and non-Kurds in the northern oil hub of Kirkuk, where the majority of the population is Kurdish, Mr. Stansfield said.

Tribal Sunni groups are clashing with fighters loyal to Al Qaeda in the western province of Al Anbar. In the South, Shiite groups are fighting for control over Basra, the oil-rich city near the Iranian border, Mr. Stansfield said. The Shiite cleric Moqtada al-Sadr’s Mahdi army militia, which is Iraqi nationalist and opposed to federalism, is coming into conflict with other Shiite groups, such as the Badr militia, that have close ties with Iran.

In addition, Sunni insurgents are fighting U.S. forces in the country’s North and center, and Shiite militiamen are attacking British forces in the South of the country around Basra, the report said.

At least 63,000 civilians have been killed in Iraq since the American-led invasion, according to the Iraqi Body Count Web site, which tracks only press reports of civilian deaths. This is likely to be a conservative total; the United Nations said in January that at least 34,000 civilians were killed around the country last year alone.

U.S. military deaths have risen every month since the intensified security efforts began in February. At least 49 American soldiers have been killed this month, according to Department of Defense statistics. Some 148 British service members have been killed since the invasion.

Mr. Stansfield recommends the better inclusion of Sunni representatives and Mr. Sadr, who has widespread support in the south and Baghdad, in the political process, and backing for Kurdish hopes of a formally autonomous state in the North of the country.