In the wake of any apparent terrorist attack, it's always the first question asked: "Who did it?"

But amid the blood and debris of Friday's U.S. Embassy bombings in Kenya and Tanzania, depressingly few clues point to a culprit. Experts on East Africa came up empty in their initial search for possible suspects or motives within the region."I'm comfortable with the notion this has nothing to do with internal African politics," said Walter Kansteiner, an Africa specialist at the Forum for International Policy in Washington. "In Kenya, opposition parties are very pro-American, so there's not the motivation to do this and, quite frankly, not the instinct or capability. It's the same in Tanzania."

The apparently well-coordinated bombings, which occurred just a few minutes apart in capital cities separated by about 450 miles, suggests the involvement of a sophisticated organization with the ability to deploy simultaneously on multiple fronts and slip across borders without arousing suspicion, according to former State Department counterterrorism chief Robert Oakley, who also served as ambassador to Somalia and Zaire.

"This is the first time we've had two coordinated explosions. It obviously required planning," Undersecretary of State Thomas R. Pickering said.

No group in Africa has ever demonstrated that kind of sophistication, U.S. officials said.

Moreover, only two of the 123 anti-American attacks recorded over the last year by the State Department took place in Africa.

Almost inevitably, initial suspicion was focused on established Middle East-based groups that have demonstrated both the desire and the capability to strike at the United States, despite the seemingly unlikely locations.

Officials noted that American Embassies in Africa would be far softer targets to hit than their heavily fortified counterparts in the Arab world.