GREENVILLE, S.C. - More than two weeks after a deadly substance was found at a Greenville-area post office, a Clemson facility was shutdown for about 30 minutes when an unknown white powder was discovered.

A worker found the substance at 6:30 a.m. and the office on College Avenue was shut, Clemson Police Chief Jimmy Dixon said.

Dixon said authorities did not yet know what the powder was. He said he didn't think the incident was terrorist-related. "Nothing at this point leads me to believe it's ricin," he said.

The post office opened about 30 minutes later and operated until about noon, Dixon said.

"There was a letter that came through that had white powder in it," he said. "It looked like white baby powder."

The State Law Enforcement Division, the FBI and postal authorities were called, Dixon said.

On Oct. 15, a deadly substance called ricin was found at a Greenville postal distribution center. The center was shut for 11 hours.

Dixon said he collected the Clemson sample himself and had his department enact its "terrorism" mode to contain the substance.

The substance was taken to the FBI in Columbia, which is expected to perform tests, Dixon said. It was unclear how long it will take before the results are known.

Information from: The Greenville News