WASHINGTON?Preliminary tests show the anthrax sent to New York and Florida were the same strain, and the FBI is pursuing ?substantive leads? in the investigation into who may have sent the poisons, officials said Wednesday.

Law enforcement and other U.S. officials said there was no evidence so far of foreign terrorist involvement in the anthrax attacks, and one official said some evidence might suggest a domestic source.

There is no evidence the anthrax was associated with a weapons program, one official said.

The investigation was moving on several fronts as authorities conducted complex tests on the anthrax that has shown up in at least four cities in recent days?including NBC News in New York and a publishing company in Florida.

After preliminary testing, said Dr. David Fleming of the Centers for Disease Control and Prevention, ?the strain in New York appears to match the strain in Florida.?