Doctors in Sudan say at least six people have been killed and more than 20 injured in protests in the port town of Suakin.

The violence broke out following the sacking of the governor of neighbouring Kassala State.

A curfew has now been imposed in Suakin as well as in Port Sudan where there have also been protests.

At the root of the violence is rivalry between two ethnic groups in the east of Sudan.

When Prime Minister Abdallah Hamdok appointed Salih Ammar as the governor of Kassala State, Hadandawa people took to the streets – blocking Port Sudan in neighbouring Red Sea State and making it impossible for the governor to start work.

On Tuesday the prime minister dismissed him – but this made people from the Beni Amer ethnic group furious as one of their own had been ousted.

The violence has highlighted the challenge the prime minister faces as he tries to reform Sudan.

As he replaces military governors with civilians some of his appointments have reignited ethnic tensions.