Vermont state police say a suspicious package sent to the Burlington offices of Sen. Bernie Sanders was not meant to cause alarm.

The state police bomb responded Thursday morning around 11:45 a.m. to the senator's Burlington offices after a suspicious package was received in the mail. The office was cleared. Church Street remained open throughout the incident.

At about 5:15 p.m., investigators decided it was not a threat and not an explosive device and people were allowed back inside.

Police Thursday initially said they thought the package was intentionally sent to cause alarm, but then later determined that was not the case.

Burlington Deputy Police Chief Jon Murad says examination techniques allowed police to see inside the package without disturbing it. "Initially those examinations suggested that there could be something inside that was potentially threatening, and further assessment was able to dispel that concern, and then we were ultimately able to deem it safe," he said.

He could not tell us why the package was appeared suspicious, but did describe the criteria it would need to meet to prompt an investigation.

"Addresses that are slightly off or people who are the intended recipient of the device who no longer work at the office. They include packages that have had too much postage put on them. They include packages that have been taped or closed in strange ways. They include packages that may have both signage or symbolism on the exterior that are indicative of trouble or of messages that are beyond what a normal package would have and make the package suspicious, hence suspicious package. But I can't talk about this specific one simply because it is an ongoing investigation. However, I will say that it met many of those things and that was why we spent a lot of time looking at it," Murad explained.

There's no word on who sent the package. The senator's office said they don't comment on matters of security.

It's the second time this month authorities have responded to the senator's offices. A suspicious package prompted a similar response Sept. 11 at the senator's St. Johnsbury office. It was later found not to be a threat.