...Finally came crowds and crowds of normal Gazans, men and women, old and young, some on bicycles, a few being pushed in wheelchairs, simply enjoying the rare sensation of freedom.

And somewhere in the teeming crowd, came people anxious to exploit the day for their own less innocent purposes.

Fertiliser, broken down into half bags for lugging through the many tunnels that arms smugglers normally use for delivery into Gaza, was to be seen as it was manhandled overland.

It was white, oily, crystalline and a dab on the tongue left a sharp, burning sensation.

In most countries fertiliser has a perfectly innocent function but in Gaza militants use it to make explosive.

"Hey, hey, hey," shouted a man as I took a photograph of a pile of fertiliser half bags.

His aggressive tone jarred with the mood the crowd as he grabbed my camera lens firmly...