The United States is building a ring of secret military bases in the Horn of Africa and the Arabian peninsula as it steps up the use of unmanned drone aircraft to strike at groups linked to al-Qaeda.
A base has been built on the Indian Ocean island chain of the Seychelles, according to leaked diplomatic cables.
Another is being established in Ethiopia, the Washington Post reported.
The US has been launching assassination missions in Somalia targeting the Islamic militant group al-Shabaab, which publicly supports al-Qaeda, for some time.
Washington already has a base in neighbouring Djibouti. Drones were used in two days of attacks near the Shabaab-controlled port city of Kismayo in southern Somalia last week.