By Jason Straziuso
Associated Press Writer
Tuesday, Oct. 23, 2001; 12:20 p.m. EDT

JACKSON, Miss. –– A tiny Coast Guard post was dusted with white granules sprayed from a small plane, the second such incident in the state in four days, authorities said.

The latest incident happened Monday afternoon at the Shore Side Detachment office in Natchez.

A Coast Guard member who was standing outside is being given antibiotics as a precaution, said Petty Officer 3rd Class Joan Farris in New Orleans.

"As far as they know it was a small white plane," Farris said Tuesday. "They are not sure if it was a crop duster."

Farris said local, state and federal authorities were notified, and a sample of the granules was taken to a state laboratory for testing.

Crop dusters in the region are fertilizing fields with small white pellets this time of year, State Agricultural Aviation Board member Bern Prewitt said Tuesday.

Meanwhile, authorities were awaiting final test results for a Mississippi River towboat and crew that was sprayed with an unknown substance by a crop duster Friday near Rosedale.

Initial tests for chemical and biological agents were negative, and the 11 crew members and towboat were released from quarantine late Sunday.

"It was definitely a criminal act, whether it was a hazardous substance or not," said Bob O'Brien, commanding officer of the Coast Guard's Marine Safety Office in Memphis, Tenn.

While witnesses said the plane near Rosedale was a crop duster, authorities would not give specifics about its color and design for comparison with the plane involved in Monday's incident. Natchez is in southwest Mississippi, 170 miles south of Rosedale.

Federal and state authorities searched crop dusters' flight records for clues to the planes' identities. The FBI is investigating but spokeswoman Deborah Madden said her office could not comment.

Crop duster pilots were shocked and angered by the incidents.

"We're here to help the farmer. We're not here to hurt people," said Karen Brunetti of Shelby Air Service.

"I talked to a couple of my friends who have flying services, and they're just bumfuzzled," said Jimmy Ervin, who owns another flying service. "They can't believe anyone would do that."