Of 54 African states asked to aid famine, only four answer the call

The absence of 50 of Africa's 54 heads of state from a pledging conference where they would have been asked to commit aid to the famine in the Horn of Africa has drawn anger from campaigners who have urged them to help the 12 million people in the region in danger of starvation.

Only four heads of state turned up on Thursday in the Ethiopian capital, Addis Ababa, for the African Union's first ever such pledging conference for a member country. The event was organised in response to the famine across five regions of southern Somalia which, the UN has estimated, it will cost $2.4bn to mitigate. Aid experts say after two years of failed rainy seasons another $1bn is needed to meet the target. So far the pledges from African governments total $46m.

Africans Act 4 Africa, a campaign launched last week by Oxfam, accused African governments of being mean. "We are disappointed that the pledges are less than the minimum of $50m that Africans Act 4 Africa set as a target," said the new group. It pointed to the work of an 11-year-old Ghanaian schoolboy, Andrew Andasi, who has raised $4,000 by knocking on doors – and, more recently, appearing on television shows – during his school holidays.

In contrast to the input of African governments, grassroots support on the continent for the people of the Horn has reached unprecedented levels, especially in Kenya where 3.5m people in the politically neglected northern region are affected by the food crisis. The Kenyans for Kenya campaign is said to be well on target to raising 500 million Kenyan shillings (£3.3m) by the end of this month.

But in the face of that fierce criticism, the continent's leading disaster relief charity has spoken out in support of the continent's governments.

Gift of the Givers president Imtiaz Sooliman said African governments have limited resources and already have powerful poverty pressures of their own. "Do not look at the amounts pledged but at the fact that Africa has for the first time in its history organised a pledging conference," he said as he left Addis Ababa on Friday.

Mr Sooliman added: "Look at who the donors were at the AU meeting. Lesotho, which is a tiny country in terrible financial straits, pledged DLRS 50,000 and Africa's newest state, South Sudan, offered DLRS 1 million. These pledges represent a historic turning point for Africa both in terms of continental cohesion and our commitment to finding African solutions," he said.

Of the African Union's 54 member states, only Ethiopia, Equatorial Guinea and Djibouti sent their heads to the AU conference, along with the head of the transitional government in Somalia.

The United States has pledged about $ 500m (£306m). The European Union has boosted its immediate humanitarian commitment for this year to £140m, while national aid pledges total a further £390m. Of those, the British government has pledged £54m. The British public has nearly matched the amount.