Washington ? Facing the prospect of a U.S.-led war with Iraq, FBI officials are working to help local law enforcement look beyond the end of the Muslim holiday that prompted the most recent terror warning and improve preparations for possible chemical, biological or radiological attacks, officials said.

In detailed advisories dispersed the past week, the FBI and Homeland Security provided information to local law enforcement about the type of biological and chemical weapons that U.S. and foreign intelligence indicates al-Qaida has obtained and tested.

Some of the advisories reported that U.S. authorities obtained evidence showing al-Qaida members had tested mustard gas and Sarin and VX nerve agents, according to law enforcement officials who saw the advisories.

Some of the advisories cautioned that chemical and biological attacks could be staged at multiple locations and synchronized to cause the greatest possible panic, officials said.

Federal officials say they have no intelligence as of yet suggesting a specific type, location or timing of a terrorist operation.