"Kassala state government is prepared to repel any attack on Sudan's eastern front," Planning Minister Ahmed Babikir Dignah was quoted as saying by the pro-government Sudanese Media Center.
Dignah, who also serves as deputy governor of Kassala state in eastern Sudan, said the rebels were massed on the Eritrean side of the border with Kassala and plotting to blow up vital installations.
Like rebels in Sudan's troubled western region of Darfur, the ethnic minority Eastern Front charge their region has been neglected by the Arab-dominated regime in Khartoum.
Two groups in the region have formed the Eastern Front to fight for people's rights in Sudan's eastern Red Sea and Kassala states.
The Beja Congress and their colleagues in the Eastern Front, the Free Lions, are both descendents of Arab immigrants to Sudan: the Beja centuries ago and Rashaidas in the 19th century.
Angered by what they say is a radically unequal distribution of Sudan's wealth from natural resources like oil, the Eastern Front rebels took up arms against Khartoum like those in Darfur and southern Sudan before them.
In late January, at least 14 and as many as 36 Beja Congress supporters were killed by Sudanese security forces breaking up a demonstration in the eastern city of Port Sudan.