A large anti-US demonstration was held in Mogadishu at the weekend
The United Nations pulled its international staff out of Somalia last week after being told flights to and from the capital Mogadishu can no longer be insured after the suicide attacks on the United States.
The European Union also withdrew its expatriate staff because of "general tension and uncertainty there" following the attacks on the US.
Many Somalis are now speculating that the adminstration in Washington may be considering some kind of military action in Somalia.
Last week, Somalia's Transitional Government denied having any links with Osama Bin Laden and said that it was ready to co-operate with the US in its fight against international terrorism in the wake of the attacks on New York and Washington.
But at the weekend there was a large demonstration in Mogadishu, in support of Bin Laden and against the US.
Al-Itihaad
The Somali group named, the Al-Itihaad organisation, is said to have branches in several countries, with one of its main bases in Somalia.
According to diplomatic sources the group has trained terrorists and been engaged in terrorist acts.
There are suggestions that it was responsible for the bombing of a hotel in the Ethiopian capital Addis Ababa, and that it also mined roads in the Ogaden region of Ethiopia.
But some observers express surprise that Al-Itihaad is being targeted, saying they are a spent force.
Indeed they have not been reported to have carried out any attacks or held any meetings since 1996.
Financial web
Our East Africa correspondent says there is speculation that the Americans may be more concerned at the capacity of groups like Al-Itihaad to channel funds towards international terrorist organisations.
Many Somalis operate an informal system of banking where large sums of money can be moved around the world on the basis of trust and acquaintances rather than using conventional financial institutions.
Elsewhere in the region, Kenya police have denied a report in one of Kenya's main newspapers, The Daily Nation, that American FBI agents are searching for those connected to the US attacks in the Kenyan coastal city of Mombasa.
The police said they were not aware of any such activity.
Somalia has been devastated by civil war since 1991 in which clan-based militias have plunged the country into anarchy.
The transitional government still does not control all of Somalia's territory.