Israel is believed to be using controversial white phosphorus shells to screen its assault on the heavily populated Gaza Strip yesterday. The weapon, used by British and US forces in Iraq, can cause horrific burns but is not illegal if used as a smokescreen.

As the Israeli army stormed to the edges of Gaza City and the Palestinian death toll topped 500, the tell-tale shells could be seen spreading tentacles of thick white smoke to cover the troops’ advance. “These explosions are fantastic looking, and produce a great deal of smoke that blinds the enemy so that our forces can move in,” said one Israeli security expert. Burning blobs of phosphorus would cause severe injuries to anyone caught beneath them and force would-be snipers or operators of remote-controlled booby traps to take cover. Israel admitted using white phosphorus during its 2006 war with Lebanon.