Health officials said Monday they have ruled out the abortion pill RU-486 in one of two deaths in women who had taken the drug. The second remains under investigation.

Earlier four women have died of a rare but deadly infection by Clostridium sordellii after undergoing pill-triggered abortions. FDA has warned doctors to watch for infection by the bug. However, the drug, also called Mifeprex or mifepristone, has not been proved to be the cause in any of those cases, the FDA said

The Food and Drug Administration says Friday that two more women have died after taking the abortion pill known as RU-486 or Mifeprex.

Reuters reports the FDA has not yet determined what caused the latest fatalities

Five women who took the abortion pill RU-486 have died from bacterial infections since its U.S. introduction nearly five years ago, the manufacturer reported on Monday.

Mifeprex already carries a warning about the possibility that women who take the drug could experience serious and sometimes fatal infections. The company is updating the label to give physicians more information to help them spot the problem, Danco spokeswoman Cynthia Summers said