Dead postal workers had anthrax

The deaths of two postal workers in Washington DC were caused by anthrax, Mayor Anthony Williams has confirmed.

Both men - who died from respiratory failure - worked at the Brentwood post office that sorted mail for the US Congress and handled the letter containing anthrax which was sent to Senator Tom Daschle.

Two other workers at the Brentwood office have also developed inhaled anthrax infections, the most deadly type of the disease.

To combat the anthrax threat, the US postal authorities have launched a $1bn security operation, which includes purchasing machines to bombard mail with radiation.

The BBC's Washington correspondent says there is now concern that hundreds of postal employees have been working for some time in an anthrax-contaminated area.