US Marines found cyanide and mustard agents in high concentrations in the Euphrates River near Nassiriya in Iraq, television network MSNBC has reported.
The network said a briefing from Marine officials was its source for the information.
The agents were found during routine tests conducted to ensure the water being used is safe, MSNBC said.
Neither Centcom officials in Qatar nor US military officials in Iraq have confirmed the MSNBC report.
Mustard gas produces painful, long-lasting blisters and often leads to blindness, while cyanide kills by preventing blood from transporting oxygen.
Last Updated: 19:01 UK, Friday April 04, 2003