The UN refugee agency said an airlift of urgent supplies for famine-stricken Somalis will touch down in the capital Mogadishu on Monday -- the agency's first such operation in five years.

A plane loaded with 2,500 emergency aid kits was expected to land in the city, where thousands have flocked since the crisis began, at about 11:00 am (0800 GMT).

The first of three planned airlifts over the coming days, the operation will provide Somalis with plastic sheeting for shelter, sleeping mats and blankets, water cans and kitchen utensils, the office of the UN High Commissioner for Refugees (UNHCR) said.

"This airlift of emergency assistance items will allow us to continue delivering aid to those displaced by drought and famine," UNHCR Somalia representative Bruno Geddo said in a statement.

"However, we need the funding support to continue to enable us to replenish our emergency stocks inside Somalia as they are being rapidly depleted as we deliver much-needed aid across southern Somalia," he added.

An estimated 100,000 Somalis have fled to Mogadishu over the past two months in search of food, water and shelter, according to the agency.

It renewed a call for funds, warning that the $65 million (45 million euros) it has received or been promised was less than 45 percent of the $145 million the UNHCR estimates is needed to deal with the crisis affecting the Horn of Africa.

The UN's food agency started airlifting aid to Mogadishu late last month.

More than 12 million in Somalia and other countries in east Africa are in of emergency assistance due to conflict and the region's worst drought in decades, according to the UN.

In a surprise move, Al Qaeda-affiliated rebels who had been controlling around half of Mogadishu dismantled their positions and withdrew Saturday, allowing Western-backed forces to assert their authority on the city.