Senior United Nations officials on Monday condemned the seizure by Somalia's Al-Shabaab group of property belonging to United Nations agencies and several non-governmental organizations working to address the humanitarian crisis in the country's south. Secretary-General Ban Ki-moon condemned the seizure in the strongest possible terms," saying that the "brazen" action prevented the relief organizations from providing life-saving assistance to those in need. "The Secretary-General demands that Al-Shabaab vacate the premises and return seized property to the affected agencies and NGOs," said a statement issued by his spokesperson. "He calls for the ban imposed today by Al-Shabaab against these humanitarian organizations to be lifted immediately." Valerie Amos, the Under-Secretary-General for Humanitarian Affairs, warned that any disruption of relief efforts threatens to undermine the fragile progress made in saving the lives of hundreds of thousands people affected by a severe food crisis caused by the devastating drought in the Horn of African earlier this year. Famine conditions could return to some of the affected areas in Somalia if relief work is interfered with, Amos said in a statement. She also called upon groups associated with Al-Shabaab to withdraw immediately from humanitarian compounds seized in the south-central regions of Bakool, Bay and Hiraan, and Lower Shabelle in the south, and to desist from any further actions which would threaten humanitarian operations and the safety of aid workers.