Somali insurgents on Monday barred the World Food Program from the famine and war-plagued Horn of Africa country, where the United Nations says four million people, half the population, needs emergency food aid.
The al-Qaeda-linked Shabaab movement, which controls most of central and southern Somalia, said food distributed by the U.N. agency had undermined local farmers and accused it of acting with a political agenda.
The group accused the Rome-based agency of distributing food that was past its expiry date, which had caused people to fall ill, and alleged that its operations was disguised support for the weak U.N.-backed transitional government.
"Given the problems caused by the food WFP distributed, the movement of Shabaab al-Mujahideen banned the operations of the agency in Somalia generally starting from today," the group said in a statement.
"The contractors working with WFP must avoid collaborating with the agency otherwise anyone working with the agency will be seen as serving the interest of WFP," the group said.
The Shabaab said they had received complaints from Somali farmers that the quantity of the WFP food aid prevented them from selling their own products at a fair price.
WFP Africa spokesman Peter Smerdon said that the organization remained determined to help up to one million people who are in need of food aid in southern Somalia, "as long as it is safe for our staff to do so."
The WFP announced in January that it was suspending its operations in southern Somalia citing months of attacks and extortion by insurgents.
"Impartial and non political"
The United Nations said the agency hoped to restart work in the area in March or April, adding the suspension was over the post-harvest period when enough food was available.
The WFP also said it would continue to send food aid to 1.8 million Somalis in other parts of the country. This included the capital Mogadishu, which is also mostly under Shabaab control.
The agency has insisted that its role in Somalia is "impartial and non political."
In November the Shabaab imposed 11 conditions on U.N. agencies and nongovernment groups working in the country, including that they do not interfere in Islam and pay a tax of at least $20,000 every six months.
A senior member of the Shabaab confirmed the ban on Sunday.
"We have already given (WFP) chances to operate in Somalia, but after failing to comply with the conditions we put forward, we totally banned WFP operations in Somalia," he said on condition of anonymity.
The WFP's website says famine in the country last August left Somalia "facing its worst humanitarian crisis since the famine of 1991/1992, with half the population -- 3.64 million people -- now in need of outside assistance".
Mired in almost uninterrupted civil conflict since the 1991 ouster of president Mohammed Siad Barre and plagued by recurring natural disasters, Somalia is often described as one of the world's worst humanitarian crises.
The Shabaab, whose leadership has proclaimed allegiance to Osama bin Laden's al-Qaeda network, has been fighting the government and its African Union allies alongside Hezb al-Islam, a smaller and more political outfit.