NEW YORK -- The FBI is advising members of a crop-dusters' group to report any suspicious buys of dangerous chemicals in the wake of the recent terrorist attacks.

The advisory went out to members of the National Agriculture Aviation Association. Randy Hale, president of Hale Dusting Service, says his and other crop-dusting companies have imposed security measures to prevent their planes from being stolen by terrorists or anyone else. Burkett's manager Shawn Root says his company is disabling planes and draining them of fuel at night.