More than half a million children in the west African area wracked by Boko Haram extremists are so malnourished their lives could be in danger unless they get aid, a UN humanitarian official has said.

The UN’s top humanitarian official in South Sudan says he saw “piles and piles” of bodies after rebels belonging to one ethnic group slaughtered members of other groups in a remote town.

War-torn South Sudan could become the scene of the worst famine catastrophe in Africa in decades without more aid and a ceasefire to let farmers reach their fields, the UN has warned.

Countries and other donors told the United Nations today they were pledging an additional £300m (€440m) for Pakistani earthquake victims, but UN officials said it was unclear how much was going to combined emergency relief efforts.