The death toll from three car bomb attacks late Monday night that blasted apart buildings in separate residential compounds occupied by Americans and other foreigners rose to at least 20 today, with scores of others wounded, Saudi and American officials said.

The suicide attacks spread terror and confusion through the night and drew condemnation from President Bush, Saudi leaders and Secretary of State Colin L. Powell, who arrived in Riyadh for scheduled talks with Crown Prince Abdullah only hours after the blasts.

Mr. Powell toured an apartment complex where the entire front was blown off. There was furniture and clothing strewn about the area around a 10-foot-deep crater and nearby there was an overturned truck that had been blasted apart.

Mr. Powell seemed shaken as he toured the site, just as a dust storm whipped through the rubble and a pungent stench from the explosives hung in the torrid air.

``This was a well-planned terrorist attack, obviously,'' he said somberly. ``The facility had been cased, as had the others. Very well executed. And it shows the nature of the enemy we are working against. These are people who are determined to try to penetrate facilities like this for purpose of killing people in their sleep, killing innocent people, killing people who are trying to help others.''

Like other officials, Mr. Powell said there was no evidence that Al Qaeda had carried out the attack, but he said it had that group's ``fingerprints.''

[President Bush reacted angrily to the attack.

``Today's attacks in Saudi Arabia, the ruthless murder of American citizens and other citizens, remind us that the war on terror continues,'' he said at an appearance in Indianapolis.

The president called the bombings ``despicable acts committed by killers whose only faith is hate.'' The crowd of 7,000 at the Indiana State Fairgrounds roared its approval when he said, ``The United States will find the killers, and they will learn the meaning of American justice.'']

Early reports by a Saudi official put the toll at 20. He said that seven Americans, seven Saudis, two Jordanians, two Filipinos, one Lebanese and one Swiss died. In addition, nine charred bodies believed to be those of the suicide attackers were found, the official said. American officials said they did not dispute those figures.

American officials said the three attacks were almost identical in method. In each case, a vehicle sped to a lightly guarded entry gate of one of three large residential compounds in the northeastern part of the sprawling capital. Gunmen shot their way past the sentries and then got inside the guardhouse to open the gate and to lower other barriers.

Then a second vehicle laden with explosives made its way into the compound, following similar routes that got them to the center where most people were retiring for the evening, before the drivers set off an explosion. A military officer at the Vinnell Arabia compound, which Mr. Powell visited, said there was a possibility that some of the perpetrators had fled at either the compound entrance or from the second vehicle before it exploded.

He said that all of the attacks took place within a few minutes of each other at approximately 11:20 p.m. and that it appeared the truck at the Vinnell complex contained 400 pounds of explosive material similar, he said.

That attackers appeared clearly to have singled out residential compounds occupied by foreigners. The Vinnell Arabia compound was home to about 500 military advisors, many retired from American armed forces, employed to help train the Saudi Arabian National Guard, which is a domestic security force.

The other two compounds were identified as Al Hambra and Gedawal, both occupied by some of the foreign community in Saudi Arabia working for businesses and trade organizations. Those compunds were home to not only to Americans and to British, but also Philippine, Turkish and other foreign citizens, as well as Saudis.

The estimates of the number of expatriots living in Riyadh ranges from 15,000 to 35,000. Some residents at the Al Hambra compound said this evening that many of their colleagues had left the country before the recent war with Iraq and had only started to return in recent weeks.

``Before the war, they asked us all to leave,'' said Jelal Berkel, 39, an employee of Saudi Snack Foods, a subsidiary of Frito Lay. ``But we said we feel secure in the compound. What a mistake.''

He said he and his wife, Elif, heard a loud clicking sound late at night, and initially thought it was firecrackers. It turned out to be automatic gunfire.

When they went to the window, he said they said they saw a huge orange light covering the sky, followed by an explosion and then intense heat. The blast blew open their windows and doors. In a videotape they made of the damage, the entire fronts of several apartments and villas had been sheered off and the contents blown about the area.

``It looks like a cruise missile or a Tomahawk or Scud missile fell into the place,'' Mr. Berkel said.

The Berkels said they were leaving Saudi Arabia immediately and they predicted other foreigners would as well, and they seemed puzzled by their own complacency until recently. Mrs. Berkel said that after the war with Iraq was over, the security gate to their compound was kept open after being closed during the war.

``You believe what you want to believe,'' she said. ``We thought it was very secure. We were just so happy and relaxed that everything was back to normal.''