Al Qaeda claimed a squad of four Iraqi homicide bombers, including a husband and wife team, carried out the Ammam attacks with explosive belts after carefully staking out the hotels for a month. Jordan interrogated 12 suspects Friday who may have helped them.

The terror group's Iraqi branch issued its third Internet statement since Wednesday's nearly simultaneous attacks, saying the four Iraqis had the Radisson SAS, Grand Hyatt and Days Inn hotels under surveillance "to achieve greater accuracy in hitting the target."

It was believed to be the first time a married couple has carried out a homicide attack. The couple bombed the Days Inn after the woman "chose to accompany her husband to his martyrdom," the statement said.

Jordanian officials have found the remains of three males believed to be the attackers but could not confirm a woman was involved. Police were scouring footage from hotel security cameras, and forensic experts were analyzing the severed head of a woman discovered at one hotel.

The Days Inn explosion happened outside the hotel after the bombers' car was unable to cross a protective barrier. As a result, the casualties at the Days Inn were not as extensive as at the Hyatt and Radisson.

In its latest statement, Al Qaeda said the bombings were carried out in response to "the conspiracy against the Sunnis," referring to the Muslim Arab group favored under Saddam Hussein's regime and now believed to form the core of the Iraqi insurgency.

Authorities have not said with certainty that Iraqis were involved, only that one of the bombers had an Iraqi accent. But there have been indications — including a letter this year from Usama bin Laden's top deputy — that Al Qaeda in Iraq leader Abu Musab al-Zarqawi wants to extend his group's influence beyond Iraq.

From the capital, Amman, to the northeastern industrial town of Zarqa, the birthplace of al-Zarqawi, thousands of Jordanians vented their fury for the second straight day and called for the terror group leader's death.

"Al-Zarqawi is rejected by everybody in Zarqa, even by his family members," said Mohammed al-Sharaa, a neighbor of the Al Qaeda in Iraq leader's clan in Zarqa.

Many of the 400,000 Iraqis living in Jordan joined the protests and called for punishing anyone involved in the attacks.

Police have detained more than 120 people, including Iraqis and Jordanians, in the manhunt for anyone who may have helped the bombers. Among those in custody were 12 people, including Jordanians, regarded by investigators as "suspects," Deputy Prime Minister Marwan Muasher told reporters.

Police were searching for eight vehicles — including a GMV Suburban and a Mercedes Benz sedan, both with Iraqi license plates — spotted by witnesses near the hotels around the time of the attacks. The six other vehicles carry Jordanian plates.

The death toll rose to 57 — including three U.S. citizens but excluding the bombers — following Friday's death of Mustapha Akkad, the Syrian-American filmmaker who produced the "Halloween" horror movies. Akkad, 75, of Los Angeles, suffered serious wounds and a heart attack in the Hyatt bombing, which instantly killed his 34-year-old daughter, Rima Akkad Monla, an American living in Beirut.

Pain and anger overflowed at several funerals.

Ashraf Akhras, whose wedding at the Radisson was targeted by one of the bombers, wept as his father's body and those of at least four relatives were lowered into the ground. A Jordanian prince offered to host another wedding for Akhras.

"There is tremendous outrage by the Jordanian public that these people have targeted just innocent people," King Abdullah II told CNN. "And I can tell you that we Jordanians, we get mad and we get even and these people will be brought to justice."

Late Thursday, Al Qaeda in Iraq issued a statement justifying the attack on the grounds that the hotels were "favorite places for the work of the intelligence organs, especially those of the Americans, the Israelis and some western European countries." But more than half of those killed were Jordanians.

Throughout Jordan, protests followed mosque sermons that performed special prayers for the victims.

"Al-Zarqawi, you are a coward! Amman will remain safe!" 3,000 protesters chanted as they marched past the capital's al-Husseini Mosque.

U.N. Secretary-General Kofi Annan visited the Radisson and Grand Hyatt hotels, where reconstruction work was under way.

"These are very dark days," said Otto Steenbeek, general manager of the Grand Hyatt, which lost employees when the Iraqi-accented bomber struck the lobby.

It was not possible to authenticate Al Qaeda's Internet statement, but it appeared on a site that has included past statements by the terror group, including Thursday's.

The new claim, signed by the group's spokesman Abu Maysara al-Iraqi, also threatened Israel. Noting that Jordan, which it described as Israel's "buffer zone," was now "within range," al-Qaida said "it will not be long before raids by the mujahedeen come" to Israel.

The statement identified the attackers by pseudonyms: Abu Khabib, Abu Maath, Abu Omeir and the wife of Abu Omeir.

Abu Khabib, identified as the leader, struck in the bar of the Radisson, while Abu Maath bombed the Hyatt, the statement claimed.

Suspicion about the bombers has increasingly fallen on insurgents fighting U.S. and Iraqi forces across Jordan's eastern border with Iraq. Al-Zarqawi, who has been sentenced to death in absentia in Jordan for terror crimes, is believed to have trained more than 100 Iraqi militants to carry out suicide bombings in Iraq and possibly elsewhere in the Middle East.

Until six months ago, few Iraqis participated in homicide operations against coalition or Iraqi forces, leaving those missions to foreign Islamic extremists, said Iraq's deputy interior minister, Maj. Gen. Ali Ghalib. "But these days a bigger number of Iraqis carry out suicide attacks," he said.