Ethiopia to Tigray forces: 'Surrender peacefully' within 72 hours

Ethiopian Prime Minister Abiy Ahmed has given Tigrayan regional forces 72 hours to surrender before the military begins an offensive on the regional capital of Mekelle.

"We urge you to surrender peacefully within 72 hours, recognising that you are at the point of no return," Abiy said in a Twitter message on Sunday evening.

Tigrayan forces could not immediately be reached for comment.

Earlier on Sunday, Ethiopia's army said it plans to surround the rebel-held capital of Tigray region with tanks and may use artillery on the city to try to end a nearly three-week war, urging civilians to save themselves.

The Tigray People's Liberation Front (TPLF), which is refusing to surrender its rule of the northern region, said its forces were digging trenches and standing firm.

"The next phases are the decisive part of the operation, which is to encircle Mekelle using tanks," military spokesman Colonel Dejene Tsegaye told Ethiopia Broadcasting Corporation.

"We want to send a message to the public in Mekelle to save yourselves from any artillery attacks and free yourselves from the junta ... After that, there will be no mercy."

The military said it has captured the town of Igada Hamus, some 97 kilometres from Tigray region's capital Mekelle. 

PM Abiy rejects mediation 

Prime Minister Abiy's federal troops have taken a string of towns during aerial bombardments and ground fighting, and are now aiming for Mekelle, a highland city of about 500,000 people where the rebels are based.

The war has killed hundreds, possibly thousands, sent more than 30,000 refugees into neighbouring Sudan, and seen rockets fired by rebels into neighbouring Amhara region and across the border into the nation of Eritrea.

Countries around Africa and Europe have urged a truce, but Abiy has so far rebuffed that. 

Ethiopian troops are facing heavy resistance and face a protracted "war of attrition" in Tigray, The Guardian newspaper reported on Saturday, citing a confidential UN assessment report.

The report said the conflict threatens to become "long and violent," destabilising one of Africa's most fragile regions.

READ MORE: Ethiopia rejects African mediation as troops close in on Tigray capital

'Waves after waves' failed?

TPLF leader Debretsion Gebremichael told Reuters news agency by text message that his forces were resisting a push from south of Mekelle while also fighting near the northern town of Adigrat after it had fallen to federal troops.

"Encircling Mekelle is their plan but yet they couldn't," he said. 

"On south front, they couldn't move an inch for more than one week. They (are) sending waves after waves but to no avail."

Reuters could not verify the latest statements on the war. 

Claims by all sides are hard to verify because phone and internet communication has been down since fighting began on November 4.

Abiy accuses the Tigrayan leaders of revolting against central authority and attacking federal troops in the town of Dansha on November 4. 

The rebels say his government has marginalised and persecuted Tigrayans since taking office two years ago.

READ MORE: Ethiopia's latest air strike hits Tigray university

Rebels asked to surrender 

Redwan Hussein, spokesman for the government's task force on Tigray, said there was still time for the TPLF leadership to surrender. 

"The government will take maximum restraint not to cause major risks for civilians," he added.

He said that while many Tigrayan special forces and militia fighters had surrendered or scattered around Adigrat, resistance was stronger on the southern front, where rebels have dug up roads, destroyed bridges and booby-trapped roads with explosives. 

He said government troops had taken high ground there and were moving forward.

Aid agencies fear a humanitarian disaster in a region where hundreds of thousands relied on food aid and were displaced even before fighting began.

READ MORE: Aid agencies scramble to respond as Ethiopians flee to Sudan