A picture shows South Sudanese refugees at a UN camp in al-Waral, in Sudan’s White Nile state, south of Khartoum, on May 18 2017.

:: Violence and arson broke out on Thursday at the biggest South Sudanese refugee camp in Sudan, which houses tens of thousands of people, a security official said.

The scale and cause of the violence at the al-Waral camp in Sudan’s southern White Nile was not immediately clear, but local police officers and government officials rushed to the camp to investigate the incident.

The UN refugee agency and the White Nile police chief confirmed there was unrest at the camp where some 50,000 South Sudanese refugees live.

“We have reports that there is disturbance and fire in Khor Al Waral camp of South Sudanese refugees,” White Nile police chief General Eltieb Gourashi told AFP.

He said senior state officials were on their way to the camp to investigate the incident.

The UNHCR in a statement said it was “aware of the disturbance” in Al Waral camp and expressed concern “that every effort be made to ensure that a peaceful environment is maintained”.

“We call on refugee leaders in the camp and the authorities and local communities in the area to refrain from actions that might further inflame the situation,” it added.

While details of the trouble were unavailable, pictures apparently showing thick black smoke billowing from the camp and burnt huts were posted on social media networks.

About 410,000 South Sudanese refugees have arrived in Sudan since a brutal civil war erupted in their country in December 2013.

South Sudan gained independence from Sudan in 2011, but it quickly fell into a civil war because of a power struggle between President Salva Kiir and his former deputy Riek Machar.