Officials said the man did not appear to be targeting Trump or others involved in the trial
Ethiopia's government has acknowledged it had more work to do to develop its democracy but also says any journalists it has detained committed crimes.
In a speech at the African Union, Obama also said Central African Republic leaders needed to commit to inclusive elections and a peaceful transition of power. Elections in October will mark a return to democratic rule after the Seleka rebels toppled President Francois Bozize in March 2013, sparking a conflict.