PIKEVILLE, Ky. — A letter allegedly containing anthrax forced the closure of Pikeville-based U.S. District Courthouse, the Main Street location of the U.S. Post Office, and several surrounding structures, late Monday morning. As of presstime the Main Street section between Huffman and Caroline avenues remained closed.

According to David Beyer, spokesperson for the FBI in Louisville, Ky., several “apparent hoax letters” were received Monday at public offices across the state including several congressional offices.

He said the letters did contain a substance in which initial field tests disproved any hazardous substances, however, the letters have been sent to the Kentucky State Police Crime Lab for additional testing. The evaluation of only one such letter has been completed by the crime lab and it was negative, Beyer said.

According to unofficial reports from both the Federal Court Clerk’s Office in Pikeville and U.S. Rep. Geoff Davis’s office in Fort Mitchell (Northern Kentucky), said the letters were sent by a prison inmate.

“I cannot neither confirm nor deny that,” Beyer said.

As the courthouse was evacuated several people were reportedly taken to Pikeville Medical Center for observation.

Numerous agencies responded to the situation in Pikeville including the FBI, Kentucky State Police, and Pike County Emergency Management Services.