An independent commission has concluded that terrorists will most likely carry out an attack with biological, nuclear or other unconventional weapons somewhere in the world in the next five years unless the United States and its allies act urgently to prevent that.

Seven years after the 2001 anthrax attacks, a congressionally ordered study finds a growing threat of biological terrorism and calls for aggressive defenses on par with those used to prevent a terrorist nuclear detonation. Due for release next week, a draft of the study warns that future bioterrorists may use new technology to make synthetic versions of killers such as Ebola, or genetically modified germs designed to resist ordinary vaccines and antibiotics.

Iran's growing industrial and medical capabilities could enable the country to produce chemical or biological weapons if it chose to do so, security expert Anthony Cordesman said in two draft reports released this month.

The revelation that F.B.I. investigators believe that the anthrax attacks were carried out by Dr. Ivins, an Army biodefense scientist who committed suicide last week after he learned that he was about to be indicted for murder, has already re-ignited a debate: Has the unprecedented boom in biodefense research made the country less secure by multiplying the places and people with access to dangerous germs?

Bush administration initiatives to defend the nation against a smuggled nuclear bomb or a biological outbreak or attack remain poorly coordinated, costing billions of tax dollars while basic goals and policies remain incomplete, according to new reports by congressional investigators.

An outbreak of a deadly disease in a virtual world can offer insights into real life epidemics, scientists suggest.

Deadly germs may be more likely to be spread due to a biodefence lab accident than a biological attack by terrorists.

Drugs intended to be used as nonlethal weapons are almost certain to kill people if used during a crisis, the British Medical Association said in a recent report.

The U.S. government is researching whether the best defense against a chemical, biological or radiological attack might one day be right in everyone's hands - or on their ears.

If terrorists ever unleashed a biological weapon, unusual molecules normally found in the blood of llamas could quickly help warn of the attack, scientists now report.