Three young men who boarded a Muni bus near San Francisco's Potrero Hill neighborhood are suspected of assaulting the driver with a bat after repeatedly being asked to put on face masks.

The incident, according to police, happened earlier this week, and the three young men reportedly boarded the bus at 11th and Division streets.

As KPIX reports, the driver repeatedly told the young men they needed to be wearing masks, which is now required on all Muni vehicles. The driver then ordered the three off the bus, at which point one of them brandished a bat and began assaulting the driver.

The driver is said to be recovering Friday from non-life-threatening injuries.

It remains unclear whether the suspects' images were captured on bus surveillance video. The three suspects remain at large.

Earlier this week, a bus driver in New York City was similarly assaulted by a male passenger over a face-mask request.

In early July, a bus driver in France was fatally beaten by four passengers after asking them to put on face masks.