On Wednesday morning, fighting broke out on the border of the Tigray area in northern Ethiopia, shattering a five-month ceasefire between rebels and the government and heightening concerns for the six million people already stuck in one of the world's greatest humanitarian crises.

Getachew Reda, a spokesman for the Tigray People's Liberation Front, which controls Tigray, stated over the phone, "we are fighting, It's an all-out offensive."

Following weeks of military buildup on both sides of the front line, Tigrayan rebels, the Ethiopian government, and local people have verified that fighting is occurring near the northern Ethiopian town of Kobo. Each side claimed that the other fired first.

The Ethiopian government claimed in a statement that a terrorist organization had struck the eastern front. They have formally violated the truce.

The Ethiopian Defense Ministry said hours later that its air force had shot down a jet transporting weapons for Tigrayan rebels from Sudan. It provided no other details. Mr. Getachew referred to the assertion as "a falsehood."

After months of escalating tensions between Prime Minister Abiy Ahmed and regional leaders who opposed his authority, the violence in northern Ethiopia began in November 2020.

Since March, however, an uneasy calm has prevailed after he and the rebels agreed to a cease-fire to allow humanitarian aid to be delivered to Tigray.

In July 2021, Mr. Abiy's administration cut off access to Tigray after rebels there evicted government soldiers from the region, marking the Tigrayans' first significant victory since the conflict began.

Although Mr. Abiy eventually yielded to international pressure and allowed some food supplies into the region, a severe lack of fuel and cash prevented the distribution of much relief, and the situation is deteriorating rapidly.

This week, the World Food Program reported that nearly half of Tigray's six million inhabitants are in "severe" need of food assistance, and the majority of the rest are in need of substantial food assistance.

Dr. Tedros Adhanom Ghebreyesus, the head of the World Health Organization, described the Tigray crisis as "the worst calamity on Earth" and accused Western nations of neglecting the suffering there, adding, "perhaps it's because of the color of the Tigrayans' skin."

Dr. Tedros, who was born in Tigray, made similar claims of racism in April, contrasting the international response to Ethiopia with the swift involvement in Ukraine.