The drones are not being used for airstrikes but for surveillance of al-Shabaab militants, U.S. officials told the BBC.
The drones are being flown from the southern Ethiopian city of Arba Minch where the U.S. military is reported to have spent millions of dollars upgrading a remote civilian airport for the drones.
The drones are part of the expanding U.S. counter-terrorism efforts in the region focusing on groups with al-Qaida connections.
The drones, which can carry missiles and satellite guided bombs, are flying unarmed because Ethiopia's government deems use of the drones sensitive, U.S. officials told the BBC.
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