These rebels say people in their area, called Darfur, is being neglected by the government.

They also say that Arabs are being treated better by the government than black Africans.

For many years there has been some tension between the two groups over land and grazing rights.

Also, Sudan as a whole has been at war with itself since 1956, apart from an 11-year period of peace from 1972-1983.

What's their government doing to help?
The government in Sudan organised a horse or camel-mounted Arab emergency army mainly made up of ordinary people to tackle the rebels.

This army is called the Janjaweed.

The Janjaweed force often carries out attacks on villages and towns taken by rebels.

Human rights groups say this army - also know as a militia - sometimes kills and steals from the non-Arab residents of Darfur.

The government says it still has control in the Darfur area but rebels deny this.

What has happened to people living in the area?
About a million have fled their homes and at least 10,000 have been killed.

At least 100,000 have gone to neighbouring Chad to find safety, but many are camped along a 600km stretch of the border and vulnerable to attacks from Sudan.

They are also very short of food and shelter, and aid agencies want to get assistance to them.

People have already been found to be suffering from starvation.

What help are they getting?
The United Nations refugee agency is flying in emergency aid to the border area of Sudan and Chad.

The agency is also looking to move the refugees to safety in camps further inland.

The UN food agency has also begun flying in aid to northern Darfur.

Aid workers want to bring in supplies by road. The government says this is safe but some people are worried the roads could be attacked.

Recently, aid workers have said it is getting easier to get supplies to the people who need it, probably because of international pressure..

Is anyone trying to stop the fighting? Peace talks started up but didn't get off to a good start when some people didn't turn up to the opening ceremony.

The government say they are trying to disarm the Janjaweed now, but the rebels say this isn't true..

The UN have said more must be done, or it could get involved.