The Oromia region was once made up of autonomous sultanates with distinct cultural traditions.
UPDATED: Ethiopia mosque grenade attack leaves at least 17 injured; deadly protests over Addis Ababa's expansion
Opposition claim 10 students killed. Social media and the limited local reports show images of bloodied protesters in towns.
The last time it was this bad was in 1984-85 when nearly 400,000 people died – but the country is better prepared this time
In the last election in 2010, the opposition took 8% of the popular vote and won just one seat out of 547.