The World Food Program (WFP) says looters in South Sudan have stolen more than 3,700 tons of food, an amount enough to feed 220,000 people for a month.

Elisabeth Byrs, spokesperson for the World Food Program, said on Friday during a UN briefing in Geneva that the agency’s warehouses in the northeastern city, Malakal, had almost been emptied.

Byrs also added she had no details on how the looting had taken place and that the agency was working to recover lost supplies wherever possible as well as trying to protect what is still left at the warehouses.

The WFP says it is seeking USD 57.8 million for emergency food aid for South Sudan, and the agency also expects to have to ask for additional funds in the future.

The theft deals a blow to the UN agency’s efforts to feed the 73,000 civilians who are sheltered at the UN bases in the country.

In addition, more than 200,000 refugees also rely on UN support in Upper Nile and Unity states, a group that has been in need of help before the latest crisis began over a month ago.

This comes as a ceasefire deal between the South Sudanese government and rebels loyal to the ousted vice president, Riek Machar, was signed on Thursday to end fighting between the two groups.

The deal is to come into effect later on Friday, in which both sides must stop fighting and put in place a verification and monitoring mechanism for the implementation of the ceasefire while allowing unrestricted access to aid workers.

Deadly violence in South Sudan broke out in Juba on December 15, 2013, when Kiir accused his sacked deputy, Machar, of attempting to stage a coup.

The conflict soon turned into an all-out war between the army and defectors, with the violence taking on an ethnic dimension that pitted the president’s Dinka tribe against Machar's Nuer ethnic group.

Aid groups say up to 10,000 people have lost their lives in the fighting, with another half million forced to leave their homes as a result of the violence.