ABERDEEN, S.D. (AP) - Tests conducted by the State Health Department's laboratory showed there were no hazardous materials in envelopes sent to the Aberdeen offices of South Dakota's congressional delegation.
The state laboratory stayed open late Friday to test envelopes mailed to the offices of Sen. John Thune, Sen. Tim Johnson and Rep. Kristi Noem.
Aberdeen Police Capt. Dave McNeil says the envelopes contained tea bags.
After the initial report, about 20 people were evacuated Friday from the US Bank building, where Thune and Johnson have offices.
Police closed off the block around the building for about two hours while officials investigated.
McNeil says an investigation will try to determine where the envelopes were sent from and who sent them.