Daniel Howden: In this endless war, the lines of battle are blurred

We had been assured there were no civilians caught between the lines in central Mogadishu.

Moving through the warren of obliterated buildings it was hard to imagine anyone could survive in the no-man's land separating the fighters of the Shabaab Islamic militia, and the combined forces of the government and the African Union. Heavy machine-guns thundered armour-piercing rounds into the Shabaab barricades and volleys of automatic gunfire came back.

Moving through a hole in the wall punched by an artillery shell, we found ourselves face to face with a sweet stall, two women dozing on a mattress with a few jars of sugary delights and some phone cards.

But then the women were on their feet, pulling their multi-coloured wraps above their knees and tucking them into the combat trousers worn beneath. Two AK-47s were slid out from under the mattress. In less than a minute there were no civilians, just two soldiers from the transitional government force.

In Somalia's endless war, the notion of frontlines, combatants and civilians have been grotesquely blurred. It's a phenomenally complex battle to join and foreign forces that have done so have fared terribly, most famously the US Rangers whose Mogadishu humbling was made famous in the film, Black Hawk Down. Ethiopia's hated occupying army left two years ago after growing weary of the war of attrition.

Gunmen are everywhere, some in uniform, many in vests and flip-flops, testament to the endlessly shifting alliances. Warlords switch allegiance weekly from the government to the Islamist militias, taking their fighters with them.

It's a war that defies the single narrative of a UN-backed government against al-Qa'ida-backed rebels that is the staple of news reports. A bewildering mesh of clan disputes, poorly understood by outsiders, sit underneath the broader conflict.

In the hospital at the African Union base, a young boy was splayed out on a blood-soaked bed, his matchstick legs suspended in the air. He had been shot three times in the groin and was slowly bleeding to death. He was not the victim of reckless peacekeepers or Islamic extremism. He was caught in the crossfire, his mother said, of an armed dispute over a watering-hole.