THE countries involved in air strikes on Colonel Gaddafi’s forces in Libya are coming under pressure to ban the use of toxic depleted uranium (DU) weapons because of the dangers they could pose to civilians. The US has refused to rule out the use of DU shells in Libya, though it claims not to have fired any so far. “I don’t want to speculate on what may or may not be used in the future,” the US air force spokeswoman, Paula Kurtz, said yesterday.