Despite a worldwide caution for traveling Americans and the arrest of 13 suspected terrorists here recently, holiday parties and tours among the U.S. community are proceeding with no apparent increase in security, while Jordanians are skeptical that all the fuss is justified.

While the U.S. State Department has said it has evidence of credible threats against Americans traveling abroad, a mostly U.S. religious friendship group of 270 people--including former secretary of state James P. Baker and his wife, Susan--is gathering here as planned for a Wednesday night dinner with King Abdullah and several days of tours.

Embassy staff and public groups are holding the usual rounds of holiday parties in private homes and public sites such as hotels, and there is no obvious increase in security around the U.S. Embassy.

Indeed, at midday today, the Marine duty station inside the embassy walls was unstaffed, a rare occurrence.

"Probably busy," a Jordanian escort replied when asked where the Marines were.

Since the arrest more than a week ago of 11 Jordanians and two others who were allegedly involved in plotting millennium-related attacks on local tourist sites and are purportedly linked to Saudi militant Osama bin Laden, the embassy here has declined all comment about the case.

However, one of the organizers of the Gathering of Friends meeting that the Bakers are attending said there was a briefing for them by embassy staff Sunday that left the impression that the concerns were not that great.

The discovery of a group said to be plotting attacks on tourists "has not affected our planning at all," said Charles W. Mendies, a business consultant from India who is helping coordinate the visit.

Mendies said he took his cue from an embassy counselor whose mother, who is in her eighties, was planning to tour Jordan. There has been no request from Jordanian or U.S. authorities to alter tour or travel schedules, and no additional security arrangements, he said.

"The perceived threat is not as big as some make it out to be," he said, adding that the sum of the advice offered by embassy staff here as the group of 270 tours holy sites in the Jordan Valley is "be careful, and [do] not be obvious."

Mendies said perhaps a dozen people canceled their plans after the State Department warning and the local arrests, but another dozen signed up to take their place. The informal group includes Christians, Jews and Muslims, and is using the approach of the millennium for a trip and meeting to emphasize interfaith cooperation.

"You want to be smart about these things," said U.S. Rep. Tony P. Hall (D-Ohio), also a member of the group. But the State Department "would rather err on the side of being overly cautious. . . . If we listened to every advisory, we would never go anyplace."

State Department officials in Washington said there is no contradiction between the calm in Jordan and the department's Dec. 11 global advisory.

"There is not an inconsistency," one official said. "Being cautious does not mean canceling your travel plans. It means keeping an eye on what's going on and keeping your wits about you. The . . . caution . . . wasn't an advisory to head for the hills and take shelter."

Another State Department official specializing in diplomatic security said all U.S. embassies have been operating under a heightened state of alert since the bombing of U.S. embassies in Kenya and Tanzania in August 1998.

As with U.S. officials here in Amman, the Jordanians have released few details about who was arrested in the roundup of terrorist suspects and why. The arrests were announced by the Jordanian prime minister two days after the State Department advisory.

Requests to the royal palace and government for more information have been declined because King Abdullah, according to a spokesman, wants the issue dropped.

The local media have added a few details, linking the group arrested here to another Jordanian, living in exile in Britain, who has been charged in absentia in connection with bombings in Jordan earlier in the decade. Other reports have tied those arrested to a local group, Mohammed's Army, active in Jordan in the early 1990s.

None of this makes sense to Jordanians, who are surprised that their country would be the target of choice for terrorists and think the alarm is exaggerated, according to local political analysts.

Obvious U.S. targets, for one thing, are scarcer here than in countries such as Egypt, and an attack on a tourist site would probably affect as many Japanese or Europeans as it would Americans. There are no U.S. military bases, and while there are plenty of U.S. fast food franchises, there are no major U.S. oil or other industrial sites. The embassy itself, meanwhile, is considered one of the most securely constructed in the world.

Coming after Abdullah's crackdown on the militant Hamas organization, there are some who say that while the arrests may have been based on credible intelligence--either from U.S. or Jordanian sources--they also offer a handy way for a new king to show he is serious about domestic security.

"I am sure they had some grounds" for the arrest, said one Jordanian political specialist who asked to remain unidentified. But "it's a nonstory here. . . . People don't believe the government. . . . They think it is a diversion, to give the impression that the regime is firm and effective."

Staff writer Vernon Loeb in Washington contributed to this report.