Flyers threatening employees have scattered in the different parts of the Golden Gate Bridge District’s buildings, pushing the agency to pursue an investigation.

Particular employees were being targeted by the materials for allegedly not settling their dues to Amalgamated Transit Union Local 1575, the bus operator’s union. The flyers were posted at the San Rafael bus yard as well as the San Rafael Transit Center.

The materials pushed other workers to lay “agonizing discomfort and distress such as isolation,”, adding it was “union tradition” in handling “freeloading scabs” to “rid them from our midst, by any means necessary, e.g. Exterminate….Exterminate….Exterminate….”

According to Denis Mulligan, district general manager, the matter came to the agency’s attention on Monday morning, prompting it to report the incident to the San Rafael Police Department. An employee has first spotted the materials.

All of the video footage will be reviewed as part of the investigation process. Employees and their identification marks will also be checked.

 “We’re confident that we’ll know who did it,” he said. “We actually know who did it.”

The investigation is expected to end by tomorrow. The worker who will be proved behind the materials will be dismissed and will be brought to the authorities.

Mulligan said the employee suspected to have disseminated the flyers was not around on Tuesday.

All of the employees specified by the threatening letter, on the other hand, were anticipated to report to the office on Tuesday, the district general manager said.

 “The most important thing is that we protect their safety,” he said. “At this juncture we believe that all of our employees are safe.”

In an email to The Chronicle, bus operators’ union president Shane Weinstein said that he asked the district to provide paid administrative leave to each employee named in the threats while the probe progresses.

“(The union) finds the letter that was posted deplorable, disgusting, has no place in this union, no place at Golden Gate Transit, and no place in the world to be honest,” Weinstein wrote.