CAIRO (AP) — Tribal clashes in eastern Sudan killed at least nine people over the past two days, Sudanese activists said Saturday, in another bout of violence that threatens to derail peace talks in a country marred by decades-long civil wars.

Sudan's transitional government launched negotiations with different rebel groups in October, in neighboring South Sudan's capital, Juba. The peace initiative is part of a plan to bring free elections to the country.

The fighting in Port Sudan, in the Red Sea province, grew out of a fist-fight between two people that ended with one stabbed to death, the Sudan Doctors Committee said, leading to his arrest.

Around 100 others were wounded in the clashes, the group said.

Officials said security forces were deployed in the city to help contain the clashes between the Bani Amer tribe and the displaced Nuba tribe. They spoke on condition of anonymity because they were not authorized to brief the media.

Port Sudan was the scene of similar clashes between the two tribes in August, killing at least three dozen people. The tribal dispute started in May over water resources in the eastern city of al-Qadarif, where seven people were killed.

Tribal clashes between Arabs and non-Arabs also erupted in the western Darfur region last week.

The clashes in West Darfur’s town of Genena killed at least 48 people, wounded 167 others, and displaced more than 8,000 families.