Jodi Sigsworth says her son Andrew, left, was not hurt when his umbrella was allegedly closed in a bus's doors, but the driver berated them after the bus stopped. (CBC)

The Coast Mountain Bus Company says it is taking seriously allegations that the doors of a bus were closed on a boy's umbrella last week and that he was pulled alongside the bus when it started to move.

The alleged incident occurred Friday afternoon, when Jodi Sigsworth and her son Andrew, 9, were trying to board the No. 22 Macdonald bus in East Vancouver.

Sigsworth told CBC News she boarded the bus, but she alleged the door was closed on her son's umbrella and the bus started to move, pulling him along on the outside.

Her initial shouts for the driver to stop went unheard because, she said, he was wearing headphones.

Andrew was not hurt, but she alleges the driver berated them both after the bus was stopped and he was able to board.

Coast Mountain Bus Company spokesman Derek Zabel said the company was investigating the incident.

"It is a priority for us. We will investigate; we will take appropriate action. As for the discipline of the driver, we don't discuss how we deal with our employees but we will deal with this very seriously," said Zabel.

It's against the rules for Coast Mountain bus drivers to have headphones on or to use cellphones while driving, Zabel said.