Ethiopian Prime Minister Hailemariam Desalegn declared a six-month state of emergency on Sunday, saying it was to restore order after weeks of protests that have resulted in deaths and damage to mostly foreign-owned factories and flower farms.
Last week, protesters also destroyed scores of vehicles, adding economic casualties to a rising death toll in a wave of unrest over land grabs and rights.
"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.
"The state of emergency is vital. It is essential to restore peace and stability over a short period of time," he said, adding the ruling Ethiopian People's Revolutionary Democratic Front (EPRDF) coalition was also looking at reforms, and planning to hold talks with opposition parties.
Hailemariam said the state of emergency was effective from Oct.8.
The violence has put a shadow over a nation where a state-led industrial drive has created one of Africa's fastest growing economies, but where the government has also faced rising international criticism and popular opposition to its authoritarian approach to development.
Last Sunday, at least 55 people were killed in a stampede in Ethiopia's Oromiya region that was triggered when police used teargas and shot in the air to disperse anti-government protesters at a religious festival.
That has added the toll to more than 450 the number of people rights groups and opponents say have been killed in unrest since 2015. A U.S. researcher was killed on Tuesday when her car was attacked by stone-throwers near Addis Ababa.
But the government also faces rising international criticism and popular opposition to its authoritarian approach to development.
The unrest has included attacks on businesses, many of them foreign-owned, including farms growing flowers for export.
Attorney General Getachew Ambaye said the decree would permit authorities to stop and search and also detain suspects without court authorisation, as well as carry out house searches.
It also bars the "preparation, distribution and exhibition of material that could incite chaos", he said in an official announcement.
The measures did not contain curfews, but Getachew said the command post set up to oversee the implementation of the legislation and chaired by Hailemariam would determine where and when to impose curfews "should the need arise".
"Failure to observe the measures would lead to imprisonment for a period of five years," he said.
Mulatu Gemechu, deputy chairperson of the opposition Oromo Federalist Congress, told Reuters that the unrest could worsen if security forces were to be granted more powers and expand 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, scores of 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 U.S. researcher was killed on Tuesday when her car was attacked by stone-throwers near Addis Ababa.