(CNN) -- A U.S. Air Force drone crashed Tuesday in the African island nation of Seychelles, an Air Force spokesman said.
There were no injuries when the MQ-9 Reaper craft went down at Seychelles International Airport on the island of Mahe. The cause of the crash is unknown, and the accident is under investigation.
The U.S. military and the Seychelles Civil Aviation Authority worked together to clean up the debris, and the runway was reopened for normal traffic.
The crash is not related to a recent incident in which a U.S. drone fell into Iranian hands, officials say. For one thing, they seem to be two different kinds of drones -- the one over Iran was apparently a sophisticated stealth-type vehicle while the Seychelles one is of more conventional design.
Iran claims it brought down the stealth drone.
The Air Force said many U.S. aircraft are in the region covered by the U.S. Africa Command, and they back "regional security missions -- including maritime surveillance, counterterrorism, counter-piracy and bilateral security engagements with partner nations."
The United States initially used armed drones to strike in Pakistan and Afghanistan, along with areas of Iraq. But the United States has been expanding the drone program because it has identified more targets outside the Afghan-Pakistan region, al Qaeda's traditional base.
Moammar Gadhafi's forces were targeted this year in Libya. And strikes have continued in Yemen and Somalia. A U.S. official said surveillance flights are now being flown from a base in Ethiopia as well.
After a brief break, the United States recently restarted a drone program from a base in Seychelles in the Indian Ocean.
Reapers have a range of more than 1,100 miles, and can reach various parts of Somalia, where al Qaeda-linked Al-Shabaab is based. A drone could even fly into Yemen, where Al Qaeda in the Arabian Peninsula is based.
An official cable leaked to WikiLeaks shows that two years ago, American diplomats agreed to get approval to arm the Reapers directly from Seychelles President James Michel for the deployment of drones for counterterrorism flights into East Africa.
The cable describes Michel's opinion of Somalia: "That country could prove a 'nest for terrorism' if the problem isn't attacked head on."