Juba, July 15 (IANS) A UN agency said on Thursday that it has started relocating "non-critical" staff from South Sudan following five-days of fighting that saw hundreds of people killed and more than 36,000 others displaced.

A statement from the UN Mission in South Sudan (UNMISS) said some staff would stay behind to run critical operations to support South Sudanese who are in need of humanitarian assistance.

"Due to the recent fighting in Juba and subsequent associated operational challenges, the UNMISS and UN agencies, funds and programmes in South Sudan have ordered the temporary relocation of some non-critical staff," the statement said, according to Xinhua.

"UNMISS and UN agencies, funds and programmes will continue running critical operations to support the people of South Sudan, including protecting civilians and providing humanitarian assistance," it said.

The move comes as several countries have evacuated their cities from the world's youngest nation given the fighting which started last week between forces loyal to President Salva Kiir and Vice President Riek Machar.

China, Italy, Germany, Britain, Japan, India and Uganda have already started evacuating their citizens from the country.

Aid workers said the humanitarian situation is dire and deteriorating. Food supplies were running low as tens of thousands of people were forced to flee their homes, taking refuge in UN bases.

Meanwhile, the UN World Food Programme (WFP) on Thursday condemned the looting of its main warehouse in Juba.

WFP said the UNMISS peacekeepers at its request did an assessment of the warehouse on the western edge of Juba on Wednesday and reported extensive looting of food.

"WFP strongly condemns the theft of food intended for the poorest and most vulnerable people of South Sudan," said WFP Deputy Regional Director Vernon Archibald.

"While the extent of the looting is not yet clear, we fear that the loss of these vital food supplies will severely hamper WFP's ability to assist the tens of thousands of people who have fled their homes because of the violence," he added.

WFP said its staff have not yet been able to reach the warehouse to confirm the extent of the losses.

Before the fighting started at the end of last week, more than 4,500 metric tons of food was in the warehouse, enough to provide life-saving food and nutrition assistance to about 220,000 people for a month, it said. It also held trucks, generators and other relief items.

Regardless of the theft, Country Director Joyce Luma noted that the WFP has already provided urgently needed food assistance to thousands of displaced people sheltering at UN peacekeeping bases, using stocks from a smaller warehouse in another part of town.

"In addition to providing food assistance to displaced people in Juba, which is our normal role, WFP has also sheltered some 3, 000 people in our main office compound, mostly women and children who fled for their lives as fighting raged around us," said Luma.