U.N. envoy Joaquim Chissano arrived in Zimbabwe for talks with President Robert Mugabe on Thursday as the country plunged deeper into economic crisis, with mass arrests of black market traders, long lines for gasoline and stampedes for scarce food like sugar. Chissano, the former president of Mozambique, was due to hold discussions with Mugabe on proposed U.N. reforms, according to Zimbabwe state radio. However the meeting was also expected to touch on growing food shortages in Zimbabwe, which used to be the bread basket of southern Africa. With an estimated 5 million Zimbabweans now acknowledged to be in urgent need of food aid, World Food Program chief James Morris is due to visit the country next week, The Associated Press reported.