the italian coast guard , which said it received on tuesday , a spokesman with save the children told cnn the group fears 400 migrants could be missing , citing testimony from survivors who said their ship carrying 550 people capsized in distress .
the italian coast guard , however , told cnn that while it can not confirm such an incident and has not yet found evidence at sea to indicate a migrant boat carrying approximately 550 has capsized with 145 rescued .