Anthrax: FBI arrest man

US government officials were today preparing to question a man detained in a town at the centre of the US anthrax outbreak.

FBI agents raided at least two apartments in Trenton, New Jersey, where three of the letters contaminated with the potentially deadly spores were sent.

Witnesses said agents took one man after carrying out a three-hour search in an apartment where four ‘‘Middle Eastern’’ men were living.

The man was understood to have been detained by US immigration authorities, and FBI agents seized several bags of potential evidence from the flat.

Two other people were reported to have been detained in areas near the Trenton post office, which has emerged as the only known source of the anthrax contamination.

FBI agents have said there is no direct link between the September 11 terror attacks, the anthrax poisoning and the raids on the apartments.

One month after the first anthrax case was confirmed, President George W. Bush said the biological attack - which has killed four and infected 13 others - was ‘‘a second wave of terrorist attacks upon our country’’.

Anthrax testing was under way at 259 postal facilities, mostly on the East Coast. Officials awaited results from 21 post offices where testing was complete.

Health authorities said anyone receiving post should keep an eye out for signs or symptoms of anthrax after the President warned that it appeared the spores could be transferred between letters.

And doctors were warned to be extra-vigilant with all patients, not just postal workers.

Mr Bush said the government was working to test post offices and other sites for spores and reassured Americans that the odds of receiving a piece of tainted mail were ‘‘very low’’.

Meanwhile in Washington, Treasury Department officials sent a ‘‘suspicious’’ letter bearing a Trenton postmark for testing as authorities finalised plans to decontaminate the Senate Hart office building, where the anthrax-contaminated letter to Senator Tom Daschle was opened.

Final approval for the decontamination plan - which involves filling the nine-storey building with chlorine dioxide gas - was expected to be announced later today.