abcnews.go.com 

The federal government has begun preparing three U.S. cities for large-scale, 10-day terrorism-response exercises scheduled this month.

Beginning sometime between May 7 and May 29, local, state and top level federal authorities will respond to simulated weapons of mass destruction attacks in three cities — Denver, Portsmouth, N.H., and the Washington, D.C.-area.

Denver or Portsmouth will face either a simulated biological or a chemical weapons attack. The D.C. metropolitan area will respond to a radiological attack drill — which could range from simply an exposed container of radioactive material to a small nuclear detonation.

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