U.S. Ambassador James McGee said the group was from the opposition headquarters in Harare, which had become a refuge. He said by telephone that embassy officials were working with humanitarian organizations to find accommodation for the group.
In Washington, U.S. State Department spokesman Sean McCormack said embassy staff did not see the group as a security risk and that they were outside the building's security perimeter.
More than 300 opposition supporters who last week sought refuge at the South African Embassy in Harare have been taken to a camp outside the capital.