Investigators in Nanaimo are asking any witnesses to come forward after a 59-year-old man was knocked unconscious in a possible hit-and-run last month.

The man was walking alone near the Wellington Beer and Wine Store between 3 and 3:30 p.m. Wed., Oct. 18 when it happened, RCMP say.

Without warning, he was knocked out and when he came to, he discovered he was bleeding from a gash in the back of his head.

The man told investigators he has no idea what knocked him out because he doesn't suffer from seizures and is in good health, but said he remembered hearing the sound of screeching tires as it happened.

People working in the area did not see the incident but rushed to the man's aid when they saw him lying on the road.

The man was rushed to a local hospital and received several stitches for the wound he suffered.

Police canvassed the area for more witnesses or surveillance footage but were unsuccessful in their efforts.

They're now asking anyone else with information to contact them at 250-754-2345 or Crime Stoppers at 1-800-222-8477.