PORTLAND, Ore. (KOIN) — A suspect was detained Wednesday morning after allegedly harassing and assaulting a TriMet bus driver in Southeast Portland, authorities said.

The Multnomah County Sheriff’s Office told KOIN 6 News the passenger, identified as Michelle Hamberg, boarded the bus and started yelling at the driver. Hamberg then allegedly continued yelling and spat on the driver after being told to stop.

Police responded to the scene just before 10 a.m. near the corner of Southeast Cesar E Chavez Boulevard and SE Hawthorne Boulevard.

The driver told Hamberg to stop again who then hit the driver multiple times, deputies said. The Portland Police Bureau said officers arrived to the scene and detained Hamberg nearby.

TriMet, which is struggling with its worst driver shortage in its history, said the incident was “simply not acceptable.” A spokesperson with the agency released the following statement to KOIN 6 News:

“We are saddened to hear of one of our operators being targeted while at work today in the community. Attacks on our employees are simply not acceptable. They are out there every day providing a vital public service, and they should be treated with kindness and respect.”

Hamberg was charged with disorderly conduct “among other charges,” MCSO said, however deputies did not specify what those charges were.

The driver, who was left unnamed, did not report any injuries.

KOIN 6 News is working to learn more.