SBS Transit has said it will take "strict disciplinary action" against the bus driver who knocked down an old woman when she was crossing the road.

A video, dated Jan 20 and which has been circulating on Facebook, shows a slow-moving SBS Transit double-decker bus hitting the pedestrian as she was crossing a traffic light junction at Upper Serangoon Road at about 9.45am. The bus, service 153, was headed towards Hougang Central at the time.

The woman, who stumbled and fell to the ground after being hit, quickly got on her feet again and walked off.

Said SBS' senior vice-president of corporate communications Tammy Tan on Tuesday: "Our bus captain committed a series of mistakes - none of which we condone. He did not adhere to strict traffic safety rules and as a result, hit an old lady. He also did not take down the old lady's particulars after she declined medical assistance. As a result, we have been unable to contact her to check on her well being. We hope she will contact us so we can render any assistance she requires.

"We will meanwhile take strict disciplinary action against our bus captain. His poor errors of judgement will not be tolerated."