About 350,000 people in Ethiopia's conflict-torn Tigray region are facing "catastrophic" food shortages, according to an analysis by United Nations agencies and aid groups.
"There is famine now in Tigray," UN aid chief Mark Lowcock said after the report's release on Thursday.
"The number of people in famine conditions...is higher than anywhere in the world, at any moment since a quarter million Somalis lost their lives in 2011."
Already, more than 90% of Tigray's 5.5 million people need emergency food aid.
Fighting in Tigray broke out in November between government troops and the region's former ruling party, the Tigray People's Liberation Front (TPLF). Troops from neighboring Eritrea entered the conflict to support the Ethiopian government.
The violence has killed thousands of civilians and forced more than 2 million from their homes in the mountainous region.
The Integrated Food Security Phase Classification (IPC) analysis concluded that more than 350,000 people were in Catastrophe (IPC Phase 5) - the most extreme warning - between May and June 2021.
"This severe crisis results from the cascading effects of conflict, including population displacements, movement restrictions, limited humanitarian access, loss of harvest and livelihood assets, and dysfunctional or non-existent markets," it said.
If the conflict deepens or humanitarian assistance is hampered, most areas of Tigray will be at risk of famine, it said. Even if aid deliveries are stepped up, the situation is expected to worsen through September.
The Ethiopian government disputed the IPC analysis, saying food shortages are not severe and aid is being delivered.
Ethiopian Foreign Ministry spokesman Dina Mufti told a news conference on Thursday that the government was providing food aid and help to farmers in Tigray.
"They (diplomats) are comparing it with the 1984, 1985 famine in Ethiopia," he said. "That is not going to happen."
But US Ambassador to the United Nations Linda Thomas-Greenfield said a humanitarian nightmare was unfolding.
"This is not the kind of disaster that can be reversed," she told a virtual US and European Union event on Tigray on Thursday.
She referred to a previous famine in Ethiopia that killed more than 1 million people, saying: "We cannot make the same mistake twice. We cannot let Ethiopia starve. We have to act now."
IPC level 5 is the most extreme warning that can be given and is split into catastrophe and famine.
Famine means at least 20% of the population "has or is most likely to have an extreme deprivation of food and face starvation, death, destitution and extremely critical levels of acute malnutrition."
In a famine, a third of children are acutely malnourished and starvation or malnutrition and disease kills one out of 5,000 people each day.
Catastrophe means less than 20 percent of the population is experiencing famine conditions, or mortality levels have not yet reached famine thresholds.
Famine has been declared twice in the past decade - in Somalia in 2011 and in parts of South Sudan in 2017.
Mituku Kassa, head of Ethiopia's National Disaster Prevention and Preparedness Committee, told reporters on Wednesday: "We don't have any food shortage."
More than 90% of people have been provided with aid, he said, and he accused the TPLF of attacking aid convoys.
"TPLF remnant forces...attack the personnel, they attack the trucks with food."
Reuters could not reach the TPLF for comment and Mituku did not provide details of the alleged attacks.
The United Nations said on Wednesday incidents had been reported where aid was blocked and humanitarian workers had been interrogated, assaulted and detained at military checkpoints.
Unnamed parties to the conflict had also looted and confiscated of humanitarian assets and supplies, the United Nations said.
UN spokesman Stephane Dujarric said there had been reports of starvation among displaced people, while there was a severe need for food in northwest Tigray after the burning or looting of harvests. He did not attribute blame.