The use of white phosphorous material is not illegal if used to create smoke screens or for illumination; but since 1980 the Geneva Convention does prohibit its use as a weapon of war in densely populated civilian areas. The brightly burning substance can cause massive burns on people caught in its blast radius, incite large ground fires and burns for long periods of time.

According to Marc Garlasco, senior military analyst at Human Rights Watch, "White phosphorous can burn down houses and cause horrific burns when it touches the skin.” Its use in the Gaza conflict is the subject of intense criticism from various humanitarian organizations.

The incident that incited the investigation, originally reported by the Israeli newspaper Haaretz, pertains to its use by an Israeli parachute brigade in a densely populated region in northern Gaza. But throughout the conflict allegations of its use came from a number of sources. On Jan. 15 The Times reported the recovery of a spent white phosphorous shell in the village of Sheikh Ajilin in western Gaza. The same day as the main UN compound in Gaza fell victim to another strike in which the flammable material is thought to have been used.

On Monday Amnesty International accused Israel of war crimes claiming that a fact finding team found "indisputable evidence of the widespread use of white phosphorus" within the region. "Yesterday, we saw streets and alleyways littered with evidence of the use of white phosphorus, including still burning wedges and the remnants of the shells and canisters fired by the Israeli army," said Christopher Cobb-Smith, a weapons expert who is in Gaza as part of the four-person Amnesty International team.

Israel indicated as recently as last week that all weapons used during its Gaza offensive comply with internationally mandated law.

By: Alberto Ramos Cordero