Ethiopia's government says it will free several prominent opposition figures as the country marks Orthodox Christmas.
Speaking on Friday, Prime Minister Abiy Ahmed said the government was making the move in a bid to achieve national reconciliation and to promote "unity".
Leaders of the rebel Tigrayan People's Liberation Front (TPLF) will be among those pardoned in the amnesty.
Government forces have been fighting the rebels for over a year in a war that has claimed thousands of lives, reports the BBC.
The surprise pardon comes amid a lull in the 15-month long conflict, which has recently seen government forces retake the initiative and capture several rebel-held towns.
Announcing the new amnesty, the government communications service said in a statement that the "key to lasting unity is dialogue. Ethiopia will make any sacrifices to this end".
"Its purpose is to pave the way for a lasting solution to Ethiopia's problems in a peaceful, non-violent way... especially with the aim of making the all-inclusive national dialogue a success," the statement added.
But there was no mention of further negotiations with TPLF rebels, who last month said they were ready to enter talks if the government released political prisoners and ended a seven-month siege of Tigray that has cut off food and medicine to the region.
According to state media, among the prominent TPLF figures being released under the amnesty are Sibhat Nega, a founding member of the party, and Abay Weldu, a former president of the Tigray region.
Leading figures from several other ethnic groups have also been released.
The pardons coincided with a visit to the country by the US Special Envoy Jeffrey Feltman, who has consistently pushed for talks to end a conflict that has destabilised Africa's second most populous state.
Mr Feltman, who announced earlier this week that he will leave his position by the end of this month, held what US State Department officials called "constructive, substantive discussions" with government officials in Addis Ababa on Thursday.
Having advanced to within 300km (186 miles) of the capital, Addis Ababa, TPLF forces have been forced to retreat in recent weeks after a resurgence from government forces.
The Tigray conflict broke out in November 2020 after Mr Abiy ordered a military offensive against regional forces in the area. He said he did so in response to an attack on a military base housing government troops there.
The escalation came after months of feuding between Mr Abiy's government and leaders of the TPLF.