AMMAN, Jordan (CNN) -- The king of Jordan on Saturday said four people carried out the suicide bombings in Jordan and "initial findings" indicate that they were Iraqis.

Meanwhile, a government official confirmed that al Qaeda in Iraq was responsible for the bloody attack.

"We are pretty sure the four suicide bombers are foreigners," Jordan's King Abdullah II told CNN. He added that it is a "possibility" that Syria was used as a crossing point.

Earlier Saturday, the Jordanian government confirmed that al Qaeda in Iraq, the group headed by terror mastermind Abu Musab al-Zarqawi, was responsible for the suicide bombings. The attacks at three Amman hotels earlier this week left 57 people dead and more than 90 injured.

A Jordanian official has told CNN that the bombers were Iraqi, and that they entered the country three days before the attacks.

Authorities know where the bombers stayed, the source said, have their passport information and presumably know where they traveled.

The attacks on the Grand Hyatt, Radisson and the Days Inn hotels on Wednesday marked the third time al Qaeda in Iraq and Zarqawi have targeted Jordan, Deputy Prime Minister Marwan Muasher said.

Al Qaeda in Iraq first claimed responsibility for the suicide bombings on a Web site often used by its terrorist network. The statement was signed in the name of a group spokesman, Abu Maysara al-Iraqi, The Associated Press reported.

The site identified the team of bombers as three Iraqis and the fourth as a woman "who chose to accompany her husband on his road to martyrdom."

Muasher said the claim a woman was involved is untrue.

All bodies from the attacks have been identified, the prime minister said, and there were "no remains of anybody that suggested" a woman.

Jordan's king has vowed that the perpetrators of Wednesday's suicide bombings will be brought to justice.

"There is tremendous outrage by the Jordanian public that these people have targeted just innocent people," he told CNN on Friday.

"And I can tell you that we Jordanians, we get mad and we get even, and these people will be brought to justice," he added.

For a second night, Jordanians held a candlelight vigil Friday in front of the Radisson hotel, where the first and deadliest of the blasts took place.

Earlier, Abdullah -- visiting the injured at an Amman hospital -- said his country was not intimidated by the attacks.

"Jordan is now part of many countries that have suffered from the senseless violence of suicide bombers, whether it's in European countries or in Arab and Muslim countries," the Jordanian king told CNN's Brent Sadler. Al-Zarqawi 'most wanted'

Al-Zarqawi is the most wanted man in Iraq, with a $25 million reward on his head.

The death toll in the bombings increased by one Friday morning to 57 -- including the three bombers -- following the death of Moustapha Akkad, a Syrian-born movie director.

The worst carnage occurred at the Radisson, where the bomber detonated himself in the middle of a Jordanian wedding party.

Abdullah has close relationships with Israel and the United States, and his nation is seen as a crucial Arab ally to Washington in the war on terror.

Abdullah appeared on Jordanian state television and said such terror attacks would only "increase our strength."

"We will pursue those criminals and those who stand behind them, and we will reach them wherever they are," the king said. "Jordan does not fear and does not accept blackmail, and those operations will never push us to change our position or our convictions.

Queen Noor, the widow of Abdullah's father King Hussein, predicted the terrorists would lose ground because of the anger over the bombings.

"I personally think they've made a significant tactical error here, because they have attacked innocent civilians, primarily Muslims," she told CNN's Anderson Cooper. "It is a sin against Islam what they have done."

The U.S.-born queen said a good friend was wounded and was in intensive care, adding that his daughter was killed.

CNN's Brent Sadler, Barbara Starr and Kristen Gillespie contributed to this report.