Addis Ababa: Ethiopia's Prime Minister Hailemariam Desalegn declared a six-month nationwide state of emergency on Sunday, saying months of unrest threatened the nation's stability.
Rights groups say more than 500 people have been killed in protests in the Oromiya region since last year, when anger over a development scheme for the capital turned into more general anti-government demonstrations over politics and human rights abuses.
The government says the death toll is inflated.
"A state of emergency has been declared because the situation posed a threat against the people of the country," Hailemariam said on state-run television.
"Vital infrastructure, businesses, health and education centres, as well as government offices, and courts have been destroyed," he said.
He also repeated earlier promises of reform and plans for dialogue with the opposition.
The state of emergency was effective from October 8.
The violence in Oromiya, Ethiopia's largest and most populous region which surrounds the capital Addis Ababa, and to a lesser extent in the Amhara province has put a shadow over a nation where a state-led industrial drive has created one of Africa's fastest growing economies.
But the government also faces rising international criticism and popular opposition to its authoritarian approach to development.
The unrest has also included attacks on businesses, many of the foreign-owned, including farms growing flowers for export.
Hailemariam did not elaborate on what the state of emergency would entail but said details would be announced soon.
Mulatu Gemechu, deputy chairperson of the opposition Oromo Federalist Congress, told Reuters that the unrest could worsen if the state of emergency meant granting security forces more powers and expanding their presence in Oromiya.
"These are peaceful protesters who have been demanding that soldiers are pulled out. This could intensify anger," he said.
Last Sunday, at least 55 people were killed in a stampede triggered when police used teargas and shot in the air to disperse anti-government protesters at a religious festival in the town of Bishoftu.
A US researcher was killed on Tuesday when her car was attacked by stone-throwers near Addis Ababa.