Ingram Micro found a second package Monday containing an unknown powdery substance at its distribution center in Millington, Tenn., said Kent Foster, chairman and CEO of the company.

Earlier in the day, a suspicious package resulted in the closure of the facility. The second package was discovered an hour and a half after the facility had reopened. The two packages came from different addresses, and local and federal officials are investigating the incidents, Foster said. Authorities took both packages to be tested for anthrax and other dangerous substances, an Ingram Micro spokeswoman said.

About 400 employees were evacuated Monday after the first package containing an unidentified powder was found. An hour and a half after they were allowed back in the building, the second package was discovered, forcing the closure of part of the distribution center, Foster said. The remainder of the building, which was determined to be safe, remained open, he said.

No employees have been tested for anthrax, Foster said.

"Until we get [laboratory] results from the first test, we will not put them through that, but we are poised to put them through that," Foster said.

The incidents are among the latest in several anthrax scares across the nation following the finding of anthrax spores at several media outlets and government offices, as well as a Microsoft facility in Nevada.

"We're right in the middle of this. Every company in America is in the middle of it," Foster said. "Some of it is real; some of it is a hoax. We don't know."

Ingram Micro could know laboratory test results from the first package as early as Wednesday and as early as Thursday for the second package found, Foster said.

The first package reportedly contained software and was shipped from a company in Ogdensburg, N.Y., which is located near the U.S.-Canada border about 58 miles from Ottawa, Ontario, Foster said. He did not know whether it was a scheduled incoming shipment or a return.

"The software is being researched, but it's not believed to be Microsoft," he said.

Earlier this week, Microsoft confirmed that a letter sent to its licensing subsidiary in Reno, Nev., contained anthrax spores.

Microsoft executives are awaiting the final test results for five Microsoft Licensing employees and a family member who were nearby when the tainted letter originating from Malaysia was opened, according to the Washoe County Health District.

Ingram Micro sent a team of senior executives from its Santa Ana, Calif., headquarters to Tennessee Monday evening.

"They're managing this with local executives and supervisors. We have decontamination people there, FEMA [Federal Emergency Management Agency] and the FBI," Foster said.

The shutdowns should not cause significant delays in Ingram Micro's delivery schedule, Foster said. Orders were rerouted to other distribution facilities, he said.

"Some orders were trapped before we could divert them. We'll get over that. It is not big and it will not cause problems," Foster said. "We will lower service levels [for a short time]. Our customers will understand."

PAULA ROONEY contributed to this story.