The FBI is investigating why six envelopes of a bacteria-containing powder were sent to the Pine County Government Center in Pine City earlier this week, according to the Star Tribune.
The courthouse was shut down and 200 employees evacuated Tuesday afternoon, after a worker found the first suspicious envelope and notified authorities. Five more envelopes with typed addresses were found in two locations in district court offices within the government center.
Friday, the Minnesota Department of Health ruled out chemical or biological terrorism, but found that the powder did contain a potentially harmful bacteria.
MDH says it needs to run more test to figure out whether the bacteria is the kind that can cause foodborne-illness symptoms like vomiting and diarrhea.
Northland's News Center reports no illnesses from contact with the powder have been reported.
MDH said it will take about two weeks to get definitive lab results.