A French mercy convoy, zig-zagging through enemy lines and mortar fire for half a day, ferried more than 100 badly wounded soldiers to safety in Croatia Sunday. Fighting continued despite a new cease-fire call by Croatia and the Serb-led Yugoslav Army.Special United Nations envoy Cyrus Vance said over the weekend that a UN-imposed arms embargo had failed. He predicted 400,000 or more refugees by the end of the year. The mercy convoy evacuated the wounded to a makeshift field hospital here after their truck hit a landmine, said a spokeswoman for the Paris-based aid group Medecins Sans Frontieres. Yugoslav Defense Minister Gen. Veljko Kadijevic and Croatian President Franjo Tudjman ordered the 10th cease-fire in Croatia in four months Saturday in a deal brokered by the European Community. Talks were to resume Sunday in Zagreb.