The US Embassy in the Samoan capital, Apia, is to reopen today after being shut down for a week for security reasons.
According to Le Samoa newspaper, Samoa police have confirmed that three people, believed to be from the Middle East, have been observed taking photographs of the building that houses the embassy.
One had already left the country for Fiji by the time the embassy was closed and police are trying to locate the other two.
The police investigation also includes a group of artists leasing the Sinalei resort in Siumu.
Village leaders believe the group may be from countries with terrorist links, but the resort owner, Folasaitu Joe Annandale, says he has checked the visitor's backgrounds and they are not terrorists or connected to any terrorist organisation.