Senior UN officials warned late Friday of civilian casualties as the battles between the Ethiopian National Defence Forces and the special forces of the Tigray People's Liberation Movement entered their second week.
About 20,000 Ethiopians have fled into neighbouring Sudan following the outbreak of fighting with growing fears that the conflict, which began as an internal political dispute, could snowball into a regional security and humanitarian crisis.
"The ongoing ethnic rhetoric, hate speech, incitement to violence and attacks prevailing in Ethiopia constitutes a serious threat to internal and regional stability and should immediately be addressed to avert further escalation of widespread violence," Pramila Patten, the UN acting special advisor on the Prevention of Genocide, and Karen Smith, the special advisor on the Responsibility to Protect, said in a joint statement on Thursday.
"We strongly urge the Ethiopian authorities to take urgent measures to protect its population from further violence and strongly encourage them to seek assistance from the international community…to aid in de-escalating the rising tensions in the country," they said.
Ethiopian officials have however been fighting back what they called "misinformation" from the battlefront, despite not providing any figures on civilian casualties. Prime Minister Abiy Ahmed has ruled out negotiations with the fighters in Tigray, in spite of calls from the UN, African Union and the Intergovernmental Authority on Development to choose dialogue.
In Sudan's Gadarif State which borders Ethiopia, the local governor, Dr Suleiman Ali Mohammed, ordered for the opening of the Umm Rakuba refugee camp after an estimated 7,000 Ethiopians crossed the border to flee the fighting in Tigray.
He told local media that he was working with the UN High Commissioner for Refugees and government refugee registration desks to get accurate data on those arriving.
UNHCR representative at Khashm El-Girba, Mr Muhammad Rafiq Nasri, said the UNHCR may airlift refugees from the border to Umm Rakuba camp.
The entry of Ethiopians into Sudanese territory continued after large groups crossed the Seteit River at night on Thursday, officials said.
The area, which suffers from fragile security, is a known route for human trafficking of migrants heading to Europe through the Mediterranean Sea.
Mohamed Ali Fazari, a political analyst in Khartoum, warned the turmoil in Ethiopia will have negative impacts in Sudan. "This increasing number will affect, economically, the situation in Kassala and Gedarif states," he told The EastAfrican.
"It is worrying that despite this deterioration of the security situation, opportunities for mediation are still very low and this will have serious implications not only for eastern Sudan but for the whole Horn of Africa region."
On Wednesday, Prime Minister Abiy dispatched Gedu Andargachew, his new national security advisor to Khartoum to deliver a message on "developments in Tigray."
The fighting broke out last week after PM Abiy ordered a military crackdown on TPLF fighters whom he accused of "crossing the last red line" after an attack on a government military camp.
"Under the TPLF, millions of Ethiopian men and women had suffered widespread political repercussions, economic as well as social marginalisation for two decades," Abiy said on Wednesday, accusing TPLF of training banned armed militia to target civilians.
"Such a cruelty cannot be addressed or redressed by sitting at a table for negotiation. Negotiation makes sense only when there is good faith and desire for peace."
Addis Ababa has also turned up the pressure on the leaders of the restive region by stripping them of immunity from prosecution.
TPLF leader and President of Tigray Dr Debretsion Gebremichael and other senior officials including Getachew Reda, Asmelash Woldesellassie, and Abay Tsehaye, were all stripped of immunity to face criminal charges, according to a statement released by the Ethiopian prime minister's office on Thursday.
The move means the TPLF leadership can no longer use their parliamentary privilege to dodge the law. The statement did not specify which criminal charges the 39 will face, although the Ethiopian government has already declared the TPLF an "extremist group."
Defence Minister Kenea Yadeta claimed the military had "rescued" certain regions of Tigray and would be installing new leaders to manage the region's affairs.
"The transitional administration will be formed in parts of the Tigray Regional State that have been set free from the extremist group of TPLF," Kenea said, according to a report by the Ethiopian News Agency.
Meanwhile Debretsion, the Tigray leader, claimed this week his region had been attacked "on a separate front" by Eritrean forces, as the TPLF fought with the ENDF on the other.
The TPLF, according to an estimate by the International Crisis Group, may have about 250,000 fighters. Government forces said they would continue to target them, as well as fuel and artillery depots.
While military casualties are not clear, the humanitarian toll continues to rise. On Thursday Amnesty International said its investigators had confirmed a "massacre" of hundreds of civilians in western Tigray.
Deprose Muchena, the Amnesty International director for East and Southern Africa, said his team had confirmed the massacre occurred on November 9 and the victims may have been casual labourers in the town. But he added that they had been unable to tell who was responsible for the massacre.
"This is a horrific tragedy whose true extent only time will tell as communication in Tigray remains shut down," Mr Muchena said. "The government must restore all communication to Tigray as an act of accountability and transparency for its military operations in the region, as well as ensure unfettered access to humanitarian organisations and human rights monitors."
On Thursday, Redwan Hussein, the spokesperson of the state of emergency committee set up to manage the operation in Tigray, said the TPLF were manipulating communication channels.
"For lack of information that everybody has, it is also true for the government because we cannot call, we cannot travel there. The only access we have is through our aircrafts which are bombarding areas where we have depots of fuel and artillery," Redwan said in a briefing.
"We don't think it will be long if we keep pushing. They will reopen it for their own sake."
The bitter history between Eritrea and TPLF came to the fore after Dr Debrestion claimed Eritrean forces were attacking his forces. Eritrea fought a bitter war with Ethiopia under the TPLF government between 1998 and 2000 and it appears the bad blood never flowed away.
Asmara denied the accusation, but some analysts think Isaias Afwerki's government may be an interested party in the conflict, sandwiching Tigray in the middle.
"This war would not have been conceivable without Afwerki's active incitement, [and] backing," argued Rashid Abdi, a Horn and Gulf researcher and analyst in Nairobi.
"What are his strategic aims?" he posed. Afwerki, Abdi observed, would be interested in overthrowing the TPLF, replace it with a weak government controlled by the friendly regime in Addis. In turn, that would end federalism in Ethiopia and plans to democratise the Horn.
Despite PM Abiy's insistence that the crackdown on TPLF would last only a few days, experts warn of a longer, more intractable conflict. "A war in Ethiopia could trigger massive displacement and transfer of populations, sending millions of refuges across neighbouring countries," Dr Mustafa Ali, Chairman of the Horn International Institute for Strategic Studies in Nairobi, told The EastAfrican.
"The Regional implications are dreadful."
According to him, an overstretched ENDF could pull all its troops from Somalia, exposing the country to al-Shabaab resurgence during election season next month, and sucking in troop contributing countries, including Kenya and Uganda, deeper into the conflict.