JUBA - Intercommunal fighting in a camp housing displaced people in the northern part of South Sudan has killed 13 people, the U.N. mission running the camp said on Friday.

The clashes between two ethnic communities living in the camp in Upper Nile State's capital Malkal first erupted on Thursday when a man was stabbed to death.

"Initial reports to the mission indicated that at least three persons have been killed and more than 20 injured with some of them receiving treatment at the mission’s hospital," the spokesperson for the United Nations Mission in South Sudan (UNMISS), Ben Malor, said in a statement.

"Later in the day 10 more people were confirmed dead in other facilities."

The camp hosts at least 50,000 people. Its number has been fluctuating since the first group of people came there at the start of a civil war in 2013.

The numbers increased when about 3,000 people fleeing fighting in neighbouring Sudan also came to the camp in recent weeks, Luke Saadala, Upper Nile's Information Minister said.

Malor said while calm was returning to the camp on Friday, the UNMISS and South Sudan's army had reinforced security in the camp and its environs.

A peace deal signed in 2018 by the major parties to civil war from 2013-2018 has significantly reduced violence in South Sudan in recent years.

But lower-level clashes between rival communities frequently flare up. Violence remains rife in areas where rights to grazing areas, water, cultivation grounds and other resources are under dispute.

Upper Nile State in recent months has been an epicentre of violence mainly orchestrated by various armed militia groups.

In December 166 people, mainly civilians, were killed and more than 20,000 others displaced in the region, according to U.N. High Commissioner for Human Rights.

Fighting at the Malakal camp in early 2016 killed at least 18 people, including two staff members of aid group Médecins Sans Frontières. (Editing by George Obulutsa and Angus MacSwan)