War erupted in Sudan in April 2023 between the regular armed forces led by the country's de facto leader Abdel Fattah al-Burhan and the paramilitary Rapid Support Forces (RSF) led by his former deputy Mohammed Hamdan Daglo.

The war has since killed tens of thousands and displaced over 11 million people, with over three million of those fleeing across Sudan's borders, according to the International Organization for Migration.

It has also precipitated one of the world's worst humanitarian crises, according to the United Nations, which has repeatedly warned of a looming famine.

The army-aligned government fled to its new de facto headquarters in Port Sudan, the capital of the eastern Red Sea state, where much of the aid to the country is also coordinated.

Eastern Sudan has thus far been largely spared the bloody warfare that has plagued much of the rest of the country.

But on Tuesday the new militia, dubbed the "Eastern Battalion" and trained in neighbouring Eritrea, said that it was deploying in the eastern Kassala state, adjacent to Red Sea state.

It said its "valiant forces led by general Al-Amin Dawoud Mahmoud... are deploying and opening up towards the eastern region after a technical and military consultation with the armed forces".

"This comes within the strategy of the Eastern Battalion to protect the land... with the security apparatus in the country," it added.

The armed forces did not immediately respond to AFP's request for comment.

The so-called Eastern Battalion is among a handful of new militias that have appeared in Sudan after receiving training in Eritrea, prompting fears over the involvement of new armed factions in the conflict.