An Ethiopian foreign ministry statement said Eritrea and Somalia’s Islamist movement are conducting disinformation.
In July, Human Rights Watch accused Ethiopia of removing people, especially those with suspected rebel links.
Ethiopia government acknowledged it had ordered the International Red Cross to stop work in the area last month.
"Various parties, in particular members of certain foreign media with their own hidden agenda and mission, have been disseminating erroneous stories alleging that the Ethiopian government was blockading emergency food aid, restricting trade, causing price hikes and burning down villages in retaliation for support given to the so-called Ogaden National Liberation Front (ONLF)," the Ethiopian statement read.
"The truth, however, is that the ONLF, a terrorist group acting in collaboration with the defunct Union of Islamic Courts and the Eritrean government, has been committing various heinous atrocities in the region."
According to the statement, the regional authorities had "ascertained beyond any doubt that the International Committee of the Red Cross Office/Delegation in the region has been serving as a source of various supplies, and as a conduit for financial and logistical support to the ONLF".
The ICRC, which was carrying out water and sanitation projects in the area, has denied accusations that it aided the rebels.
Ethiopia’s eastern Ogaden region shares a long and porous border with Somalia, and most of its people are of the Somali ethnic group.
The ONLF has fought for the secession of the Ogaden region since the early 1990s.
It accuses the government of blockading the region, and producing a "man-made famine".