A 71-year-old Swansea, Massachusetts school bus driver has been fired for allegedly urinating inside the bus with students on board Monday morning.

Investigators say the bus driver, whose name was not released, was on the way to Hoyle Elementary School when he pulled over and told students to move to the back of the bus.

“The driver then allegedly relieved himself while sitting in the driver’s seat,” according to a press release from Swansea Public Schools and police. “Through the investigation, it is currently believed that no students on the bus witnessed the driver’s actions.”

The driver then completed the trip and dropped students off at school. An investigation was launched after some students reported the unusual behavior to their teachers. So far, no charges have been filed against the driver.

There were 12 Pre-K to Grade 2 students on the bus at the time. All their parents have been notified.

The Swansea Police Department is investigating and school officials filed a report with the Massachusetts Department of Children and Families.

“This is a matter we take extremely seriously,” Swansea Public Schools Superintendent Scott Holcomb and Police Chief Mark Foley said in a statement. “This type of behavior in the presence of children, especially young children, is unacceptable, and we will continue to look into the incident.”

The driver is an employee of Amaral Bus Company, which provides transportation services to Swansea Public Schools. The district is reviewing its relationship with the company after the incident.