We flew into the region, unsure what reception we could expect from the commanders of al-Shabab, the radical Islamist insurgent group, viewed by some as al-Qaeda's proxy in the Horn of Africa.

Our plan was to stay overnight in a town called Wajid - until we learned that al-Shabab had just publicly beheaded three men in the area and shot dead a community leader.

We changed our schedule fast.

We were travelling with the United Nation's World Food Programme, which, despite operating in one of the world's most dangerous environments, is managing to feed some 3.5 million Somalis.

"It is very, very difficult," said WFP's deputy country director Denise Brown.

Four of their staff have been killed since August last year.

But she acknowledged "a level of pragmatism" in al-Shabab and "a recognition that humanitarian help is needed. We don't negotiate [with them]. We discuss".

We flew into Buale region, on the banks of the wide, green Juba river.

A senior al-Shabab commander agreed to talk to us on condition of anonymity.

Bearded and apparently jovial, he confirmed an influx of foreign jihadists to the region - many thought to be from Pakistan - and welcomed their presence.

"We're all fighting for the same religion," he said. "We know we are hated by the international community, but al-Shabab has its own structure and strict rules.

"We apply Sharia law to everyone. We don't oppress people and [that's why] it's peaceful here now."

'Sold out'

He bitterly condemned the head of Somalia's transitional government, Sheikh Sharif Sheikh Ahmed, who is clinging to power in Mogadishu, protected by more than 4,300 African Union troops.

"He is far from Islam," he said. "He's sold out his own religion."

In Buale, no-one we spoke to was ready to criticise, or even discuss, al-Shabab, and its strict interpretation of Sharia law.

Moderate Islamic group Ahlu Sunnah is bitterly opposed to al-Shabab

Local elders said there had been no amputations or stonings in the area, but politely told us it was best not to talk about politics.

Recent rains have eased some concerns about food shortages in Buale.

But further north, the United Nations is warning of yet another humanitarian emergency.