A £6,400 fine, half suspended, was imposed on the Ethiopian Football Association for the conduct of the team's supporters during their opening African Cup of Nations match against Zambia in Nelspruit on Monday.
Fans threw missiles, including plastic vuvuzelas, on to the pitch after Tassew was sent off 10 minutes before half-time for a flying kick on Zambia's Chisamba Lungu.
CAF's disciplinary committee has imposed a two-match ban on Tassew for violent conduct.
The referee showed the keeper the red cad as he was being carried off the pitch on a stretcher. The Group C match ended 1-1.