Two sisters accused of punching and dragging a female Coast Mountain Bus driver by the hair made a brief court appearance in Vancouver provincial court Wednesday.

Molly Robinson, 20, and Delores Pearl Robinson, 22, who are both charged with one count of assault, made separate appearances before having their cases put over to later dates.

Molly Robinson, leaves court after her lawyer tells reporters she will be pleading not guilty. (CBC)

The assault charges stem from an incident last week when a passenger reported three men and three women on a Coast Mountain Bus openly drinking liquor.

The female driver pulled over and asked them to leave the bus. The three men did, but the three women — one of whom is 17 years old and too young to be named — assaulted the bus driver.

The judge issued "no-go" orders against the pair, meaning they are not allowed on a transit bus for the duration of the trial.

Nathan Woods​, the president of the union representing Coast Mountain Bus drivers, wants rules pertaining to those orders changed. He says

Nathan Woods says drivers don't have access to the pictures.

"If it's given by the judge, it's really hard to enact if we don't have any idea who that is," said Woods. "We'd like to be able to see who those people are."

Assaults on bus drivers increasing

Transit police spokesperson Anne Drennan says incidents like these are increasing.

Delores Robinson appeared in Vancouver provincial court Wednesday charged with assaulting a female bus driver. Her case was adjourned to the following day. (CBC)

"It's a serious problem. It's a top priority for us because the numbers are increasing," Drennan.says.

"This year since the first of January we've had 52 incidents reported to us."

Police say both sisters have had hundreds of negative contacts with the authorities.

Molly Robinson's lawyer says she will be pleading not guilty.