A Somali-based Islamic militant group is the chief suspect in a missile attack and deadly suicide bombing on Israeli targets in Kenya, U.S. officials said Friday.

Al-Ittihad al-Islamiya (AIAI) is a prominent militant organization in Africa linked to Osama Bin Laden's al Qaeda network, the officials said.

On Thursday, suicide bombers crashed an explosives-packed vehicle into a Mombasa hotel and missiles nearly brought down an Israeli passenger jet with 261 people aboard. While officials suggested an al Qaeda connection in the attacks, they stressed it was too early to be sure who was responsible.

At least 19 people, including one American, were being held by Kenyan authorities Friday for questioning in the attacks.

Officials said among those being held were a Spaniard, six Pakistanis, and four Somalis. Two of the detainees were reportedly carrying American passports.

The hotel manager of a Mombasa resort said the pair, a man and a women, said they were from Florida. They were apparently trying to check out of another local hotel two hours after a suicide bombing left 16 people dead.

Ben Wafula, manager of Le Soleil Beach Club, said the pair were detained after his hotel staff made a routine call to police. Officials in Kenya had requested local hotel owners call police to notify them of any people checking out following the blast.

While U.S. government officials confirmed an American woman and her Spanish husband were arrested, they said the pair were not involved in the attacks and should be released soon.

On Friday, Kenyan authorities unveiled two missile launchers they said were found near the end of the runway where the Israeli plane narrowly missed being shot out of the sky. The plane later landed safely at Tel Aviv's Ben Gurion Airport.

There were also unconfirmed reports in the Kenyan media that witnesses saw a light plane flying over the hotel at the time of the attack, dropping clusters of small bombs.

Although a previously unheard of group, The Army of Palestine, has claimed responsibility for the attacks, experts say such synchronized strikes have all the hallmarks of an al Qaeda operation.

One of three suicide attackers involved in the hotel bombing was identified as Abdullah Ahmed Abdullah -- a name that matches one of the most wanted al Qaeda terrorists sought by the FBI.

Another was identified as Faed Ali Sayam. That name also is similar to the name of a wanted al Qaeda terrorist. Both of the men were indicted in connection with the deadly 1998 twin U.S. embassy bombings in Africa that killed 224 people and injured 5,000.

Kenya's vice president Musalia Mudavadi said he has not ruled out al Qaeda in the attacks, citing the 1998 twin U.S. embassy bombings.

"We can't rule out the group that struck at us in 1998," Mudavadi said, adding Kenyan intelligence had received reports the country could be targeted again by terrorists.

In a faxed statement to Reuters, the Army of Palestine said it sent attackers to Kenya to "make the world hear once again the voice of Palestinian refugees, and to cast light on Zionist terrorism in the West Bank and Gaza."

The group said the attacks were timed to mark the eve of the anniversary of the Nov. 29, 1947, decision by the United Nations to partition Palestine and allow creation of a Jewish state.

However, the Army of Palestine is previously unheard of and the claim has yet to be verified.

Two children were among the three Israelis killed in the hotel bombing. Ten Kenyans were also killed, including a traditional African dance team welcoming tourists. More than 80 others were wounded.

Gilad Millo, a spokesperson for the Israeli Foreign Ministry, said 235 Israeli tourists, including 15 injured in the blast, flew home Friday. The bodies of the three Israelis killed in the attack were also onboard the evacuation flight.

Israeli Prime Minister Ariel Sharon said the Mossad spy agency would investigate the attacks along with his country's defence ministry.

"Israel will hunt down those who spilled the blood of its citizens. No one will emerge unscathed," he said, shortly after defeating Benjamin Netanyahu in a Likud leadership primary Thursday.

In Canada, Foreign Affairs Minister Bill Graham issued a statement condemning the bombing.

"The deaths of these innocent civilians at the hands of terrorists are tragic and senseless," Graham said. "This attack reminds us all that we must remain vigilant in the global war against terrorism."

A Muslim cleric in London said militants sympathetic to al Qaeda warned of an attack in Kenya in Internet chat rooms and in emails one week ago.

"Militant groups who sympathize with al Qaeda warned one week ago that there would be an attack on Kenya and they mentioned Israelis," Sheikh Omar Bakri Muhammad, leader of the radical London-based al Muhajiroun group, told Reuters.

"They said in chat rooms that there would be something good in East Africa, that a heavy price would be paid," he told Reuters.

With reports from Reuters and The Associated Press.