Nairobi - Somali gunmen have killed a driver for the United Nations World Food Programme (WFP), the third this year, a spokeswoman for the WFP said Friday.

Hassan Abdi was shot on Thursday while transporting food aid from Mogadishu to provincial areas, the WFP said.

"Somalia is one of the most difficult places for humanitarian agencies to operate, and it appears to be getting more dangerous," Denise Brown, WFP Somalia's deputy country director, said in a statement.

The Horn of Africa nation has been in a state of anarchy since the overthrow of dictator Mohamed Siad Barre in 1991.

Fighting has intensified since transitional federal government troops and their Ethiopian allies wrested control of the capital Mogadishu from the Union of Islamic Courts
(UIC).

Al-Shabaab, the UIC's armed wing, has been waging a guerrilla war ever since and hundreds of thousands have fled the vicious fighting in Mogadishu to live in makeshift camps.

The WFP believes that a combination of the conflict, drought and soaring food prices mean that 3.5 million Somalis could be dependent on food aid by the end of the year.

"We urge all parties to ensure the safe passage of humanitarian staff and cargo across the country, especially at a time when we are trying to feed more people and need to double food deliveries," Brown said.

The WFP's deliveries also face a threat at sea, and on Thursday the organization called on naval powers to provide escorts to protect its aid shipments off the pirate-ridden Somali coast.

The UN Security Council recently approved incursions into Somali waters to curb piracy, which the weak transitional government is powerless to prevent.

However, the WFP said that nobody has volunteered to replace a Dutch frigate that will end its tour of duty on June 25. (dpa)