30 powder-laced letters sent to US banks

WASHINGTON: US authorities are investigating at least 30 letters containing suspicious powder that have been sent to banks in seven cities.

The FBI said initial tests on the powder have come up negative for dangerous toxins. Additional tests are continuing.

A law enforcement official said Tuesday the letters were mailed to Chase bank branches in Chicago, Cincinnati, Dallas, Denver, Newark, New Jersey, Oklahoma City and Washington.

The letters all appear to be from the same source, and began showing up at the banks on Monday, the official said. The official spoke on condition of anonymity because he was not authorized to discuss the matter publicly.

An FBI spokesman in Oklahoma says the letters sent there indicated the threat was ``based on past actions of the bank.''