International incident or local tribal raid? Looking at the fragmentation on the map, I think the latter more likely.
Oh, it's not like if Germany suddenly crossed into Belgium, but it's still newsworthy. Ethiopia has a history of making incursions into Somalia to root out rebel groups. These skirmishes always cause a great deal of consternation amongst certain groups since Ethiopia is still a Christian majority country. Expect the required calls for Jihad any day now, as if there was anyone in Somalia not already fighting to listen.