Looters from rebel Tigrayan forces held aid staff at gunpoint in the town of Kombolcha, the United Nations said.
They stole large quantities of essential food supplies – including some for malnourished children.
Northern Ethiopia is facing mass starvation amid an ongoing civil war between Tigrayan and government forces.
After more than a year of fighting, more than nine million people are in need of critical food supplies in the Tigray, Amhara and Afar regions, the UN says.
A spokesman for the UN, which runs the WFP, said its staff there had faced “extreme intimidation” during days of looting in the industrial hub of Kombolcha in Amhara.
He added: “Such harassment of humanitarian staff by armed forces is unacceptable. It undermines the ability of the United Nations and all of our humanitarian partners to deliver assistance when it is most needed.”
The spokesman also accused military personnel of commandeering three WFP humanitarian trucks and using them for their own purposes.
That led to the decision to halt food distribution in Kombolcha and nearby Dessie, two strategic towns in Amhara that sit on the road to the capital Addis Ababa. The Tigrayan rebels have not commented on the allegations that their fighters stole food aid.
The Ethiopian government recently announced that it had recaptured the towns from the Tigray rebels. But the rebels said the army had only recovered areas they had abandoned.
BBC
As soon as the Abiy government withdrew its forces from Tigray, the TPLF leaders made it public that they will settle their scores with the Amharas. They invaded the Amhara and Afar regions by unleashing their human waves or what can be called the Tigray Tsunami. The invading Tigray human Tsunami has wrecked havoc in both regions and was able to advance to 200 kilometers from the capital. The Tigray human Tsunami can not make its ways back and the only thing it can do is lose its force and ebb. Ebbing in this case means losing almost all of its force or surrender. I think the TPLF will not be able to muster enough force to unleash more Tsunami. But the Amharas and Afars can send more devastating Tsunami into Tigray.
You call these freedom fighters? These are mujrims(thugs) of the third kind!!! What do you call thugs who terrorize unarmed civilians? What do you call armed hooligans who murder unarmed civilians? We have rightfully designated Al-Shabaab, Al-Qaeda, ISIL and many other armed vagabonds as ‘terrorists’ for the sane crimes. Right? Well, we have the same goons over there also. I don’t see a better term fitting the bill either.
Make that: for the same crimes