A large number of civilians have been brutally killed in Ethiopia's Tigray region amid fighting between the local and federal governments, Amnesty International announced on Thursday.
A top UN official has also said that necessary aid supplies to hundreds of thousands of people in northern Ethiopia are at risk because of the conflict there.
Fighting in Tigray between the federal government and a regional force broke out eight days ago.
Hundreds have reportedly been killed as fears of an escalating conflict grow.
As a result of the fighting at least 7,000 civilians have crossed the border into Sudan. They fled either the fighting itself or the fear of attack and there are concerns that many more have been forced from their homes but are still living within Tigray.
During a press briefing on Thursday, UNCHR representative in Sudan, Axel Bisschop told reporters the agency estimates half of the refugees are children.
According to Bisschop, Ethiopians are crossing a river into Sudan using several boats at one of two border crossings.
"The people who have arrived are coming with very little concessions, most of them have come in a healthy condition, we have had information of some who are injured and have been taken to a nearby clinic to be treated," Bisschop said.
Defence Minister Kenea Yadeta said it would not be long before the TPLF leaders were on trial. He also talked of appointing an interim administration in areas taken by federal troops.
Last week, Ethiopia's federal government announced a six-month state of emergency, giving them broad security powers.Parliament has voted to strip dozens of MPs from Tigray of their immunity from prosecution.
The current round of tensions in Tigray started in August when Abiy's government delayed scheduled elections because they said the risk of Covid-19 was too high. Officials in Tigray held their own election in September anyway, with more than two million people turning up to vote.
In retaliation, the federal government withheld funding from the TPLF leadership in Mekelle, promising to send it directly to local leaders instead. It set off a tit-for-tat series of recriminations and rhetoric between the regional and the federal government that has been steadily building.
Around 150 people from "ethnically diverse" backgrounds have been detained in the capital Addis Ababa and various parts of the country, on suspicion of colluding with TPLF to incite "conflicts and carrying terror attacks," according to a statement from the taskforce.
The TPLF was the most powerful member of Ethiopia's ruling coalition for many years but Mr Abiy curbed its influence after coming to power in 2018 on the back of anti-government protests.
Relations got worse last year after Mr Abiy - who won the 2019 Nobel Peace Prize for ending a two-decade conflict with Eritrea - dissolved the ruling coalition, which was made up of several ethnically based regional parties.