UK aid agency Oxfam has warned a new humanitarian catastrophe, like that in Darfur, could happen in Chad if ethnic conflict is not brought under control.
More than 120,000 Chadians have been forced from their homes
Inter-ethnic fighting along the border with Darfur has displaced tens of thousands of Chadians in the past year.
This followed attacks on villages, with many burned to the ground.
Oxfam's comments come as the United Nations Security Council prepares to consider whether to send a peacekeeping force into eastern Chad.
Eastern Chad and Darfur have a similar ethnic make-up, with nomadic Arab groups and black African farmers both seeking access to land and scarce water points.
Chad and Sudan have both accused the other of backing rebel groups.
Attacks on civilians in eastern Chad have been steadily increasing, but the scale of the violence has now reached such levels that comparisons with neighbouring Darfur are inevitable.
More than 120,000 Chadians have so far been forced from their homes in brutal inter-ethnic attacks that bear all the hallmarks of the violence seen across the border in Sudan.
One aid workers says there are not two sides to the conflict any more, there are several.
There are Chadian and Sudanese rebels in the area and Arab Janjaweed militias, accused of widespread atrocities in Darfur, operate on both sides of the border.
Chadian men on camel and horseback are mirroring the attacks carried out by the Janjaweed in Darfur.
Oxfam says that eastern Chad must not be allowed to become "another Darfur".
Chad's border with Sudan is already home to some 200,000 Sudanese refugees and together with the newly displaced Chadians almost half a million civilians there are now completely reliant on outside help.
The BBC's Orla Guerin in Chad says that new camps for displaced Chadians are being set up near the old camps for Darfur refugees.
Aid workers warn this is causing tensions and competition for scarce resources like water and wood.
The UN Security Council is preparing to discuss proposals to send a peacekeeping force to Chad but a decision is not expected immediately.
Chad's President Idriss Deby is broadly in favour of a force, and the UN has realised that peacekeeping troops may be the only way to prevent another Darfur from developing.
1. Chad says Sudan government-backed militias are attacking villagers in Chad. Some 200,000 Darfur refugees are also in Chad
2. Sudan accuses Chad of backing the Darfur rebels
3. Chad says it will send troops to help CAR fight the rebels
4. CAR says Sudan backs rebels who have seized towns in CAR