Hardline rebels have dismissed the declaration made by the UN earlier this week that there is famine in two regions of southern Somalia under rebel control.
The rebels maintain that there is a drought not a famine and that the famine statement has political motivations.
Al-Shebab insists the ban on specific aid agencies operating in the drought struck regions they control remains in place.
A spokesman for al-Shebab, Sheikh Ali Mohamud Rage, said that 'those earlier banned groups are not welcome to serve in our area of control.'
Former Irish President and UN High Commission for Human Rights Mary Robinson has warned that a new generation of children are dying from famine and drought in the region- nearly 20 years after she last visited the African nation.
Mary Robinson, writing in the Irish Sun, described the current plight of sick and under-nourished children as 'heart-wrenching.'
'Somalia's people are at the centre of a perfect storm - years of conflict, very high food prices, the worst drought in decades and reluctance on the part of the international community to help has left them in a desperate situation.'
Yesterday, The US and the UN stressed the 'acute urgency' of the severe drought spreading through east Africa, after the world body declared a famine in southern Somalia.
During a meeting with UN Secretary-General Ban Ki-moon, US National Security Adviser Tom Donilon pointed to the 'critical role' of UN agencies such as the World Food Program and UN Children's Fund (UNICEF) in responding to the crisis, and vowed Washington would support these efforts.
The pair 'stressed the acute urgency of the situation in the Horn of Africa and discussed focused ways to generate sufficient international contributions and ensure that food and other assistance reaches people in need as quickly as possible, particularly in Somalia.'
Tens of thousands have already died in Somalia in recent months, according to the UN's Food and Agriculture Organisation.
Elsewhere, Islamist rebels seized Somalia's newly appointed women's minister as she took office, heightening security fears for aid groups.
Armed men abducted 32-year-old Asha Osman Aqiil in Balad, a town north of the capital Mogadishu, a day after she was named the country's minister for women and family affairs.
