United Nations peacekeepers warned today that Haiti’s capital could quickly descend into rioting if three million hungry, thirsty and traumatised quake survivors were forced to go longer without emergency aid. The warning came as aid agencies battled to deliver tonnes of aid to Haiti’s capital in spite of blocked roads, a clogged airport and shattered ports. Looters have emptied food shops and scuffles broken out among survivors fighting over scarce water as the wait for help drags on. Brazil’s Defence Minister, Nelson Jobim, warned that the Brazilian-led peacekeeping force could struggle to cope if desperation spilled into violence. “We are...