Secretary of State Colin Powell deplored the terror bombings in this capital city, saying the attacks bore the "earmarks of Al Qaeda."

Powell shortened a meeting with young civic leaders interested in modernizing Saudi society to get a briefing from U.S. Ambassador Robert Jordan on the bombings at three residential compounds. But he spent most Tuesday engaged in talks with Saudi officials.

Powell, who had been awakened after midnight in Amman, Jordan, with word of the attacks, called the bombings an act of cowardice.

One of the subjects already on the agenda for his talks with Saudi officials was cooperating in the fight on terrorism, along with pursuing a Palestinian-Israeli peace accord.

In addition to the Americans lost, Powell said "there was a large loss of life of others."

Powell gave the assessment after a briefing from Jordan upon his arrival here from Jordan.

"Terrorism strikes anywhere, everyone," Powell said. "It is a threat to the entire civilized world."

Powell was greeted in Riyadh by Prince Saud al Faisal, the Saudi foreign minister, who expressed his sorrow and vowed to cooperate with the United States in fighting terrorism.

"It is no consolation, but these things happen everywhere," Saud said.

"The blood of Saudi citizens was mixed in this tragic event with Americans'," he said. "It should increase our efforts, it should make us not hesitate to take whatever measures are needed to oppose these people who only hate, who only kill, and for no purpose whatsoever."

A U.S. official said several members of the Saudi national guard perished in the attacks.

The U.S. official also said British, German, French, Australian and other Arab citizens were among he casualties.

Surrounded by a phalanx of aides and security guards, Powell visited one of the blast sites, a complex for employees of the Vinnell Corp., a Virginia firm. The attack there killed seven Americans.

The charred wreckage of an overturned truck lay in the rubble that was once the front of the four-story building. A U.S. flag dangled from the roof.

Vinnell has a contract to train Saudi military and civilian officials.

By chance, 50 of 70 American employees of Vinnell who resided at the building were on a training exercise and away from the complex.

Powell spent 10 minutes at the scene before departing for Moscow. His stay in Saudi Arabia lasted about six hours. In Moscow, Powell planned to discuss preparations for President Bush's visit to St. Petersburg on June 1.

Before leaving Jordan, Powell said the attacks in Saudi Arabia "once again remind us that terrorism is a global phenomenon" and that "the United States will not be deterred" in trying to root out the Al Qaeda network.

"I believe Al Qaeda has been weakened, but it has not been destroyed," Powell said at a news conference after authorizing $700 million in additional U.S. aid to Jordan.

The string of attacks occurred in quick succession Monday night, capped by a fourth explosion early Tuesday outside the headquarters of a joint U.S.-Saudi owned company in Riyadh.

If Al Qaeda was responsible for the bombings, Powell said, "it illustrates it can still strike" and means "we have to redouble our efforts to go after terrorists" by tracing the network's finances and strengthening U.S. defenses against terror.

"All it says to me is the war continues," Powell said of the Bush administration's anti-terror campaign. "We have made some progress, but it is not over."

Jordanian Foreign Minister Marwan Muasher also condemned the attacks in Saudi Arabia and expressed his government's sympathies for the victims. "This will only strengthen our resolve to find a solution to all the problems of the region," he said.

Powell, however, said he did not consider the bombings to be related to the Arab-Israeli dispute and said the United States will not be deterred in pursuing peace.

He said the administration had been concerned about the situation in the Persian Gulf region for some time.

An agreement Powell signed with Minister of Planning Bassem Awadallah sets the ground for transfer of $700 million in additional assistance to cash-strapped Jordan this year to offset Jordan's losses from the war in Iraq.

Jordan's trade with Iraq amounted to $700 million last year, making Baghdad the largest importer of Jordanian goods. Jordan also depended on Iraq for all its average need of 90,000 barrels of oil per day, receiving half of it at preferential prices and the other half as a gift of the deposed Iraqi president, Saddam Hussein.

After meeting with Powell, King Abdullah II endorsed the road map for peace between Israelis and Palestinians being touted by the United States and other countries , especially its provision for "an independent Palestinian state on Palestinian lands" by 2005.

A Royal Palace statement said he and Powell discussed during a two-hour meeting how to resuscitate Israeli-Palestinian peacemaking and what to do about the reconstruction of Iraq after the U.S.-led war. Abdullah pressed for swift formation of "a national government in Iraq which could take the lead in that country," the statement said.