Trent Barton have praised the driver of the bus where a passenger assaulted two women.
The first assault happened when a woman caught a bus travelling from Wirksworth to Derby at about 7.30am on Saturday, June 25.
During the journey, she assaulted an 80-year-old woman by banging her head on a seat.
When the bus reached Belper, the offender stepped off and assaulted a second woman by pushing her to the floor.
The offender then continued her journey to Derby.
She was described as white, in her mid-20s, with shoulder length dark hair. She was wearing a tracksuit and multi-coloured socks, and was carrying a Nike sports bag.
Police believe that both attacks were unprovoked and they want to hear from anyone who may have seen the woman in Derby since this morning.
Director of Service Delivery, Tom Morgan, said: “The safety of our customers and staff is absolutely paramount.
“As this is an ongoing investigation we can’t comment on the specifics, however we are proud of our driver, they have the highest reputation in country and are trained to deal with situations like this.
“All of our buses are fitted with several CCTV cameras and we’ll be reviewing the footage and assisting the police with their inquires.”
Police are appealing for information after the passenger on a bus travelling to Derby assaulted two women.
Anyone with information should call PC Matt Moore on 101, quoting incident 181 of June 25.