"I ask the African continent...to look hard at how they can contribute to alleviating the suffering," Erastus Mwencha, the deputy chair of the African Union, said in a statement released Friday.

"Around the globe, everyone must dig deep into their pockets to rescue the people of Somalia from the abyss they find themselves staring into," he added during a one-day visit to Somalia's war-torn capital Mogadishu.

The conference is to bring together African heads of state, members of regional economic blocs and international organizations .

The AU has donated $500,000 to address the crisis in the Horn of Africa. But the United Nations on Friday said a total of $2.48 billion was required in order to reach those suffering in the region.

Somalia is the worst-affected country, with some 1.25 million children in need of urgent life saving care, according to UNICEF. This month, the UN declared famine in two areas of the country, the first time famine has been announced this century.

The AU's representative for Somalia, Jerry Rawlings, visited Somalia earlier this month, prompting him to call on African countries to provide more support.

"This is not a time for second thoughts, or any hesitation. Not for more than twenty years has the continent faced such a catastrophe of food shortages that we are seeing today in the Horn of Africa," Rawlings, a former Ghanaian president, then said.

Ongoing violence between Somalia's Islamist al-Shebab militants and pro-government troops has exacerbated the food crisis.

On Friday, fighting broke out in Mogadishu, killing three African Union troops whose bodies were dragged through the streets, according to witnesses.

"Two gunmen shot a legislator near his hotel tonight, they shot him in the head and shoulder and he died instantly," Somali security official Liban Mohamed told AFP.

Witnesses said Kalif Jire Warfa was gunned down at around 7:30 pm (1630 GMT).

"He left Maruwas mosque when they shot him dead," witness Idris Yusuf said. "The killers escaped before police arrived at the scene."

There has been a surge in attacks in Somalia's war-ravaged capital since the African Union troops backing the government on Thursday captured positions previously held by the hardline Shebab movement.

Shebab Islamists have vowed to topple the Western backed transitional government and drive out the African Union force in Somalia (AMISOM) troops supporting it. Most lawmakers travel in Mogadishu under escort.

The Al-Qaeda inspired Shebab have been losing ground in the capital in recent months however as pro-government troops and AMISOM have clawed their way back to several key positions.

Clashes took place in the city on Friday but calm was restored over the weekend, an AFP journalist said.

The ongoing violence has hampered relief efforts as aid agencies try to deliver food to Somalia's drought victims.

The United Nation's World Food Programme (WFP) began airlifting supplies to Mogadishu last week despite battles in the city.

About 12 million people are affected by the devastating drought across the Horn of Africa, the worst to hit the region in decades.

The UN has declared a famine in two regions of southern Somalia but the effects have been felt more widely across the country, as well as in parts of Djibouti, Ethiopia, Kenya and Uganda.

Relief efforts have also been hampered by a ban on some humanitarian agencies by the rebels who controls much of southern Somalia.

The group has denied there is a famine in Somalia, saying the crisis is being exploited by external enemies.

Shebab spokesman Sheikh Ali Mohamud Rage has claimed that local Muslims are adequately addressing the drought crisis, saying in a speech on rebel radio that there is no need for assistance from "an outside enemy or non-Muslims".

He said the hundreds of thousands of refugees who have been streaming across the Somali border into the mainly Christian countries of Ethiopia and Kenya in search for food were being lured there "so that their faith can be destroyed".

The UN children's agency UNICEF has said 1.25 million children are in urgent need of life-saving support in southern Somalia.