The China National project included construction of a 932-mile pipeline from Sudan to the Red Sea.

CENTERFORSECURITYPOLICY: Center For Security Policy

But the north has the pipeline, refinery and the export terminal at Port Sudan on the Red Sea.

BBC: South Sudan in Kenyan oil pipeline deal

Most oilfields are in the landlocked south, which needs northern pipelines to Port Sudan on the Red Sea to export the stuff.

ECONOMIST: Sudan's split

The alert follows the discovery of a red dye, called Sudan 1, in chilli powder used in the sauces.

BBC: NEWS | Health | Cancer alert over pasta sauces

Israel is particularly worried by Iran's eagerness to warm relations with Sudan and Eritrea, a strategic spot on the Red Sea that could threaten Israeli shipping.

ECONOMIST: Iran and Israel in Africa

Mr. RUPP: Well, east up by the Red Sea is perhaps the poorest region of Sudan, and there is a feeling that at least some of the tribes in that area have been excluded from discussions, and the concern on the part, I think, of the Sudanese government as well as others of us that there--that could be a next area of conflict.

NPR: U.N.'s Annan Hears Sudan Refugees' Stories