Key facts
- Letters with unknown substances were sent to US election offices.
- The FBI and US Postal Inspection Service are investigating.
- The substance in Oklahoma was determined to be non-hazardous.
Federal authorities are investigating "potentially hazardous" letters containing "suspicious substances" that have been sent to congressional and state election offices around the US. The FBI and the US Postal Inspection Service (USPIS) said they were trying to trace the "suspicious mailings", some of which were intercepted before they were received. The Louisiana secretary of state's office was evacuated after a staff member opened a package on Tuesday, but has since reopened after law enforcement found no evidence of harmful substances. The Ohio secretary of state's office was the intended recipient of a letter containing white powder, but the USPIS had intercepted it. Senator Chris Murphy, a Connecticut Democrat, was also sent a letter containing a suspicious substance, but it was intercepted before reaching the office. The New York State Capitol and the Wyoming State Capitol also received suspicious packages. The suspicious mailings come just weeks before the US midterm elections.