Health authorities in Panama said Thursday that they have identified four cases of the birth defect microcephaly linked to the Zika virus, according to AP. The Health Department's chief epidemiologist said all four cases occurred among mothers of the Guna Yala indigenous group. Dr. Israel Cedeno said two of the four babies died at Panama City hospitals. Mothers from outlying provinces often travel to the capital to give birth, so it was unclear where they were infected. None of the four had been identified as having had Zika before giving birth. In all four cases, either the mother, the baby or both tested positive for Zika. Panama has had 264 confirmed Zika cases, with 11 in pregnant women.