A state of emergency has been declared in Sudan's Red Sea state after ethnic violence left at least 16 people dead.
The country's new interim government has also dismissed the governor of the eastern state and the regional security chief.
It is not clear what caused the clashes, which raged between the Bani Amer and Nuba groups in Port Sudan from Wednesday until Saturday.
For the first time firearms had been used, suggesting there had been internal and external interference to fuel the conflict, the government statement said.
Port Sudan is the capital of Red Sea state and is an important shipping route. Most of the country's trade passes through the port, which is also used by South Sudan to export oil.
Sudan has recently emerged from months of turmoil with a power-sharing agreement between civilians and the military, following the ousting of its long-term leader, Omar al-Bashir.