The United Nations has declared a state of famine in some parts of southern Somalia where the worst drought in over half a century is the cause for thousands of deaths.
The announcement on Wednesday signals the need for more aid to the worst affected regions of Southern Bakool and Lower Shabelle.
UN official Mark Bowden said malnutrition rates in Somalia were among the highest in the world, and that they would dangerously spread in the coming months.
"If we don't act now, famine will spread to all eight regions of southern Somalia within two months, due to poor harvests and infectious disease outbreaks," Bowden said.
"One in three children have suffered from severe food shortages, imperiling their lives," he said.
"More than ever, Somali people need and deserve our attention... whether we are donors, members of humanitarian organizations, or parties to the conflict."
A UN statement from earlier in the day said: "Across the country nearly half of the Somali population - 3.7 million people - are now in crisis, of whom an estimated 2.8 million people are in the south."
In all, more than 10 million people are affected and need emergency help, the UN said.
'500,000 children at risk'
UNICEF said earlier this week that at least 500,000 children were at risk of death in the Horn of Africa while the International Committee of the Red Cross has said one in 10 children in parts of Somalia could die from starvation.
Countries affected across the region include parts of Kenya, Uganda, Ethiopia and Djibouti, while the United States on Tuesday also urged secretive Eritrea to reveal how severely it has been hit by the drought.
Famine is officially defined as when two adults or four children per group of 10,000 people are dying of hunger every day and 30 percent of the population is acutely malnourished.
The office of the UN High Commissioner for Refugees said on Tuesday it was seeking further security guarantees from armed groups in Somalia in order to deliver greater amounts of assistance and prevent more hungry people from becoming refugees.
Al-Shabab controls the majority of the country, including pockets of the capital Mogadishu.
Al-Shabab surprised aid workers two weeks ago with a pledge to allow relief agencies "with no hidden agendas" greater access to opposition-held territory.
Security guarantees
The World Food Programme (WFP) suspended its aid operations across much of southern and central Somalia in early 2010 after al-Shabab ordered the UN agency to halt operations in areas under its control.
The WFP is seeking security guarantees to access these areas and the ability to distribute and monitor aid there, Emilia Casella, a spokesperson, told reporters.
The UN said on Monday it had started airlifting food to opposition-held areas and that al-Shabab had abided by a pledge to allow relief workers free access.
UNHCR has stepped up its work in southern Somalia, distributing aid to 90,000 people in recent days to areas including Mogadishu with another 126,000 due to receive supplies on Tuesday, Adrian Edwards, a spokesman, told a media briefing.
"We need significantly better access than we have at the moment to address an emergency of this scale," he said. "We need guarantees of safety on the one hand, the assurances that the humanitarian nature of our work is going to be respected."
"What we believe, and what we have observed, is with the massive movement of population outside of the country, some of the fighting forces have realized that they needed to allow humanitarian assistance to come in," Raouf Mazou, UNHCR deputy director for the Horn of Africa told reporters. "For how long that will last is something that we don't know."
PHOTO CAPTION
Somalis from southern Somalia stand behind barbed wire in a line to receive aid at a refugee camp in Mogadishu, Somalia, Saturday, July 16, 2011.
Al-Jazeera