The Ethiopian government is facing new pressure from the US to slow down on the crackdown on the Tigray region for dialogue, with some rights groups warning of possible war crimes in the area.
Just about 24 hours to the end of the second ultimatum issued by the Ethiopian Prime Minister for the Tigray People's Liberation Front to surrender, the US government said both parties must choose dialogue for the sake of civilians.
A statement from the US National Security Council indicated that Washington supports the African Union move to send special envoys to Addis Ababa.
"The United States calls for mediation in Ethiopia and supports the efforts led by (South African) President Cyril Ramaphosa and the African Union to end this tragic conflict now," the Council said.
The statement signalled renewed pressure from the US, which had last week said it would focus more on peace than mediation, as both parties had hardened their stances to fight.
Dr Abiy has since last week rejected calls to de-escalate and choose dialogue with the TPLF which he has described as 'criminals', 'junta' and 'fugitives from justice.'
Last week, President Ramaphosa, the current African Union Chairperson, appointed ex-presidents Joachim Chissano of Mozambique, Ellen Johnson-Sirleaf of Liberia and Kgalema Motlanthe of South Africa to be special envoys to Addis Ababa to help "mediate" the conflict.
But Addis Ababa said the three leaders would meet the Premier for "one on one" talks but not mediation with the TPLF.
The African Union initiative was endorsed by the UN Secretary-General António Guterres as a measure "towards ensuring a peaceful, stable and prosperous Ethiopia."
The conflict in the Tigray region escalated on November 4 after Prime Minister Abiy ordered his troops to crack down on the TPLF after they reportedly attacked a military camp manned by the Ethiopian National Defence Forces.
TPLF has ignored a previous three-day ultimatum to surrender.
On Sunday evening, Dr Abiy issued another 72-hour amnesty to the fighters or else they face the wrath of the government.
On Tuesday, Redwan Hussein, the Ethiopian State Minister for Foreign Affairs and the spokesperson of the Emergency Taskforce on Tigray, said the amnesty had seen fighters allied to the TPLF surrender.
"Using the government's 72-hour period, a large number of Tigray militias and special forces are surrendering," Redwan said in a statement without indicating the numbers.
"Many have surrendered through the Afar region, and the remaining forces are surrendering peacefully."
On Monday, Dr Abiy listed 10 attempts he tried to negotiate with the TPLF, all of which he claimed were rejected, leading to the current conflict.
But as Ethiopia prepares to launch attacks on the capital of Tigray in Makelle, rights watchdogs are warning against attacking civilian sites as this could constitute war crimes.
"As Ethiopian federal troops begin preparations to encircle Makelle, Amnesty International reminds all parties that deliberately attacking civilians and civilian objects is prohibited under international humanitarian law, and constitutes war crimes," said Deprose Muchena, Amnesty International's Director for East and Southern Africa, on Monday.
The rights groups said they were alarmed after Ethiopian military spokesman Col Dejene Tsegaye called on civilians in Makelle "to save themselves from any artillery attacks and free yourselves from the junta ... After that, there will be no mercy."
"Treating a whole city as a military target would not only be unlawful, it would also be considered a form of collective punishment," warned Laetitia Bader, Horn of Africa Director at the Human Rights Watch.
The Ethiopian government has since argued that there had been "misleading translation" of the Colonel's statement.
Both the TPLF and the ENDF have since accused each other of killing civilians and destroying civilian installations. But Tigray has been under information blockade with limited access.
A statement issued on Tuesday by the Emergency Taskforce said there has been "great care to protect civilians from harm during the law enforcement."
"Due care for the safety of civilians will guide our approach in the final phase of operations being carried out by the ENDF."