An al-Qaida in Iraq front organization yesterday claimed responsibility for an attack Thursday by a suicide bomber that killed 20 people in Anbar province, including three Kane'ohe Bay Marines, as the U.S. military stepped up pressure on extremists in northern Iraq.

The claim posted on a militant Web site and attributed to the Islamic State of Iraq said the bomber blew himself up among a gathering of the "heads of apostasy" — a reference to U.S.-backed Sunni tribal leaders who were attending a meeting in Karmah, 20 miles west of Baghdad.

"They sold their souls to the American devil for a cheap price," the statement said. "Therefore, the soldiers of the Islamic State of Iraq have launched an open war against them."

Three Marines assigned to the 2nd Battalion, 3rd Marine Division, Marine Corps Base Hawai'i were among the victims — Lt. Col. Max A. Galeai, 42, of Pago Pago, American Samoa, commander of Marines in the area; Capt. Philip J. Dykeman, 38, of Brockport, N.Y., head of the battalion's Fox Company; and Cpl. Marcus W. Preudhomme, 23, of North Miami Beach, Fla., an administrative clerk.

Also killed were the mayor of Karmah, several key tribal figures and two interpreters, U.S. and Iraqi officials said.

It could not be determined if the statement was actually issued by the Islamic State, which is an al-Qaida-controlled coalition of Sunni extremist groups.

However, U.S. officials say they suspect al-Qaida was behind the attack as part of a campaign of revenge against Sunni community leaders who turned against the insurgency and cooperated with U.S. and Iraqi authorities.

BOMBER IN POLICE GARB

The Sunni split with al-Qaida, which gained steam two years ago, cost the movement much of its base in the vast Anbar province, the heartland of Iraqi's Sunni Arab community and former center stage of the Sunni insurgency against U.S.-led coalition forces.

Although details of the Karmah attack are still sketchy, a suicide bomber dressed in a police uniform reportedly detonated an explosives belt during a meeting of tribal sheiks opposed to al-Qaida in Iraq.

The attack happened two days before U.S. officials planned to formally hand over security responsibility for Anbar to the Iraqis — a sign of the security transformation in the largest of Iraq's 18 provinces.

U.S. authorities postponed the ceremony Friday because of a forecast of sandstorms, which struck Anbar and areas of western Baghdad yesterday as predicted.

FAMILIES MOURN

Meanwhile, family and friends of the fallen Marines mourned.

In a report today in Pacific magazine, Galeai's sister, Joan Galeai, said she protected her brother when they were growing up on Tutuila in American Samoa.

"But I couldn't protect him during his tour of Iraq," she said. "But he will always be by my side and in my heart forever."

Joan Galeai said her brother's death is a tremendous loss to the close-knit family.

Her mother, Kalala, who is visiting relatives in Seattle, was especially shaken by the news, the magazine said.

Galeai said the last time she saw her brother was earlier this year in Honolulu, shortly before he deployed to Iraq for his second tour of duty in the Middle East country. Like others who knew him, she described Galeai as caring, a natural leader, and devoted to his wife, Evelyn, and their three daughters and one son.

Galeai graduated from Oregon State University in 1988, and joined the Marines out of college. His service awards include two Bronze Stars, the Purple Heart and five Meritorious Service Medals.

Preudhomme followed his older brother into the Marines, according to a report in the Jacksonville (Fla.) Times-Union.

"Marcus always had high standards and high expectations of himself," said Disiree Downing, a family friend.

According to Preudhomme's sister, Jessica, the 2004 Fletcher High School graduate had visited relatives recently, and he and the family spent New Year's in New Orleans.

She told the Times-Union her brother had a thirst for knowledge and received a number of academic honors in school.

"Some kids just come and want to do one thing," she said. "He was one who wanted to learn everything."

Josh Carey, a former teacher of Preudhomme's at Fletcher High, told the First Coast News Web site in Jacksonville, "He's the kind of kid that as a teacher you come to school every day looking forward to the opportunity to teach." First Coast News is run by WTLV NBC-12 and WJXX ABC-25.

Preudhomme joined the Marines in 2005, and was sent to Hawai'i the same year.

His awards include the Purple Heart and the Combat Action Ribbon.

Relatives and acquaintances of Dykeman could not be reached for comment yesterday. However, the Marine Base in Kane'ohe issued a statement that said Dykeman joined the Marines in June 1991 and arrived in Hawai'i in May 2007.

Dykeman was the recipient of more than two dozen medals and ribbons, including the Purple Heart and two Navy and Marine Corps Commendation Medals.