NAIROBI, Jan. 5 (Xinhua) -- The UN World Food Program (WFP) said Tuesday it has been forced to suspend its operations in southern Somalia due to rising insecurity.

WFP said in a statement issued in Nairobi said rising threats and attacks on humanitarian operations, as well as the imposition of a string of unacceptable demands from armed groups, have made it virtually impossible to continue reaching up to one million people in need in southern Somalia.

"WFP is deeply concerned about rising hunger and suffering among the most vulnerable due to these unprecedented and inhumane attacks on purely humanitarian operations," the statement said.

The UN agency said its offices in Wajid, Buale, Garbahare, Afmadow, Jilib and Belet Weyne in southern Somalia are temporarily closed, and food supplies and equipment have been moved, along with staff, to safer areas in order to ensure that food assistance continues to reach as many vulnerable people as possible.

WFP said its humanitarian operations in southern Somalia have been under escalating attacks from armed groups, leading to the suspension of humanitarian food distribution in much of southern Somalia.

"Staff safety is a key concern for WFP and recent attacks, threats, harassment and demands for payments by armed groups have decimated the humanitarian food lifeline, making it virtually impossible to reach up to up to one million woman and children and other highly vulnerable people," it said.

WFP said it was continuing to provide life saving food distributions in the rest of the country, including the capital, Mogadishu, reaching more than two-thirds of the hungry it has been targeting, or 1.8 million people.

In addition, the agency said resources and relief workers are being re-deployed from southern areas in the event that people start moving away from areas where food distributions have been suspended.

WFP said the agency was an impartial, non-political humanitarian agency that has been working in partnership with the people of Somalia for more than 40 years, providing assistance to the poorest of the poor throughout Somalia's years of conflict and before.

"The recent pressures on our work from armed groups in southern Somalia are impeding our humanitarian mandate. Even in good years, Somalia is only able to meet 40 percent of the food needs of its population through internal production," WFP said.

In the last five years, WFP said local production has averaged only about 30 percent of food needs in the Horn of African nation which has been without effective central government for more than two decades.

WFP said its working closely with its partners to pre-position supplies and prepare to provide assistance to any population movements either within Somalia, or across the country's borders into neighboring countries.