Suspicious packages were sent this week to election offices in more than 20 states, leading to an FBI investigation, triggering evacuations and rattling staff, according to a CNN survey of state offices and Associated Press reporting.

The FBI and U.S. Postal Service on Tuesday were investigating suspicious packages that have been sent to or received by elections officials in more than 10 states, but there were no immediate reports that any of the packages contained hazardous material.

Election officials in at least sixteen states, including Connecticut, have received suspicious packages and letters, raising concerns about safety.