Some Somalis have fled to Ethiopia for fear their children may be forcibly conscripted by Islamist insurgents, a UN refugee official told the BBC on Thursday.

The UNHCR’s Alison Oman told the British news network some mothers at refugee camps in Ethiopia told her they left Somalia as they had nothing left to buy-off the militants.

The Al-Shabab terror group, which has been linked to Al-Qaeda, controls most of south and central Somalia, including two large regions worst affected by the famine.

The United Nations officially declared a famine in Somalia last month, as the worst drought in 60 years endangers some 12 million people in the African nation.

Al-Shabab banned many aid agencies from the territory it controls two years ago, making it impossible to offer aid to those affected by the famine.

Tens of thousands of Somali residents have fled to the capital, Mogadishu, or to refugee camps in neighboring Kenya and Ethiopia.

Oman, who is UNHCR’s senior nutritional specialist for the Horn of Africa, told the BBC Somali mothers she had interviewed in refugee camps in south-eastern Ethiopia told her they left their villages often when their last animal died.

“The animals are their insurance,” she said. “The animals are the bank accounts of these families.”

The drought is causing a severe food crisis in Kenya, Ethiopia, Djibouti and Somalia. Weather conditions over the Pacific means the rains have failed for two seasons and are unlikely to return until September.

Since the beginning of 2011, around 15,000 Somalis each month have fled into refugee camps in Kenya and Ethiopia looking for food and water, the BBC reported.

Al-Shabab is making things worse by forcing rural families that go through their areas to give them the animals or the sorghum they have, Oman said.

“A couple of mothers said to me the fear was that if they didn't have the animals to give and grain to give, then al-Shabab might forcibly conscript children,” she added.

Oman said she had also heard about cases where families had been given small amounts of food for a child to be conscripted.