US using white phosphorus in Fallujah seige

Via boing boing, which singles out the following paragraphs for your consideration from the San Francisco Chronicle‘s reporting about U.S. drive into heart of Fallujah:

“Some artillery guns fired white phosphorous rounds that create a screen of fire that cannot be extinguished with water. Insurgents reported being attacked with a substance that melted their skin, a reaction consistent with white phosphorous burns.

Kamal Hadeethi, a physician at a regional hospital, said, ‘The corpses of the mujahedeen which we received were burned, and some corpses were melted.'”

And how, do you suppose, can they tell that a corpse melted by an incendiary shell had been a fighter rather than a civilian?