A civilian post office in the Pentagon complex has been closed after traces of anthrax were found.

Bayer AG said it will "resolutely" fight several legal claims that have emerged in the US against the validity of its patent on anti-anthrax drug Cipro.

Mail to America’s capital was today being put through bacteria-killing irradiation machines, in the first step in a plan to prevent more anthrax attacks.

The number of Americans taking anthrax antibiotics at the Government's advice is nearing 10,000.

The antibiotic Cipro has gone from relative obscurity to part of America’s new vocabulary in less than two weeks.