The International Red Cross has begun distributing food aid to more than 1 million people in famine zones in Somalia controlled by Islamist militants.
The aid agency is says it has held difficult negotiations with al-Shabab, which banned many Western aid agencies from its territory two years ago, the BBC reports.
A continuous trucking operation will take the food from the coast, deep into areas controlled by the militant Islamist group.
The UN has declared a famine in six regions of Somalia - mostly in al-Shabab areas.
Tens of thousands of people have fled to seek food aid in the capital, Mogadishu, or in camps in neighbouring Kenya and Ethiopia.
Last month, al-Shabab began moving people out of displacement camps run by local charities in Islamist areas, and returning them to their villages, where it said it wanted them to prepare land ahead of the rainy season.
But the BBC reports no crops are expected to be ready for harvest until January and aid workers said a massive food distribution operation would be needed for months to come.
The Red Cross says the aid distribution is its biggest such operation anywhere in the world.