Associated Press

RIYADH, Saudi Arabia — Four suspects with apparent ties to al-Qaida were arrested in connection with the recent suicide attacks on three housing compounds in Riyadh that killed 25 bystanders, including eight Americans, officials said Sunday.

It was the strongest sign yet that Osama bin Laden’s terrorists — who have carried out deadly strikes from Nairobi to New York — may have played a part in the bombings at complexes housing foreigners. Nine attackers died.

Interior Minister Prince Nayef said the four suspects knew about the May 12 attacks but did not take part in them. A Saudi official said they were arrested in the past three days.

Asked whether the four men in custody belonged to al-Qaida, Nayef said, “All indications point to that.”

Nayef said investigators identified three of nine badly mangled bodies of the Saudi attackers in the Riyadh blasts. Prince Saud, the Saudi foreign minister, has said there were a total of 15 men who are believed to have taken part in the attacks.

The three identified attackers were among 19 suspects being sought in connection with the seizure of a weapons cache discovered May 6 near one of the compounds. The 19 were believed to be receiving orders directly from bin Laden and had planned to use the seized weapons to attack the Saudi royal family and American and British interests.

American intelligence officials had worried that al-Qaida was preparing a string of attacks on so-called “soft targets,” including lightly defended buildings and civilians, though there has been no definitive evidence linking the Saudi-born bin Laden’s terror group to the Riyadh blasts.

Within hours of a U.S. warning Thursday of possible new attacks, terrorists struck Friday in Morocco, killing 28 people and 13 attackers, and injuring about 100 others. Investigators suspected two militant Islamic groups, also with ties to al-Qaida.

Nayef said no connections between the Morocco attacks and the explosions in Riyadh had been confirmed.

“I think the resemblance between the two explosions is there, but we await further information from Moroccan officials,” Nayef said.

New terror strikes could not be ruled out, he said.

Al-Qaida has been blamed for the Sept. 11, 2001, attacks on the United States; the October 2000 bombing of the USS Cole in Yemen that killed 17 American sailors; and bombings of the U.S. Embassies in Dar es Salaam, Tanzania, and Nairobi, Kenya.

It espouses a militant form of Islam and opposes what it considers Western attempts to control the Arab world, and has criticized the Saudi royal family for its close ties to the United States.

Nayef called for “a concerted international effort” to crack down on those who plan such attacks.

More than 60 FBI and other U.S. investigators are assisting Saudi authorities with the probe into Monday’s attacks. U.S. officials have said Americans would help — not run — the investigation into the attacks. Eight Americans were killed.

Nayef said the Americans had come to examine “the sites and we welcomed them based on that, for examining only.”

Nayef could have been trying to counter domestic criticism that his government is ceding control to the Americans. But the remarks contrasted with those by Adel al-Jubeir, a Saudi foreign policy adviser.

The Americans are “helping us with the investigation,” al-Jubeir said on Fox News Sunday.

“They’re providing support to us,” he said. “They’re sharing whatever information they have. They’re sharing their expertise.”

Al-Jubeir was a last-minute replacement on three talk shows for Prince Bandar bin Sultan, the Saudi Ambassador to the United States, who al-Jubeir said was called home on a mission related to terrorism.

No details on the mission were disclosed, but Prince Bandar is known for handling some of his country’s most delicate diplomatic tasks and for his close relations with the U.S. administration.

Earlier Sunday, Lebanese Prime Minister Rafik Hariri, who has close ties to Saudi Arabia, toured the scene of the bombings and said Islam was torn by a struggle between its moderate and extremist factions. One Lebanese died in the attacks.

“There is a struggle between good and evil,” Hariri said. “There is a struggle between those who want Islam to be a universal, respected, just and moderate Islam whose believers can be proud, and a small group of people who want to depict Islam as (a religion of) murder, terror and destruction.”

The bombing victims were also from Australia, Britain, Ireland, Lebanon, Jordan and Switzerland.

Nayef said the kingdom was serious about fighting religious extremism, but that did not mean it would alter its Islamic character.

“A separation of religion and state will not happen, this is a country of faith,” he said.