PENTICTON, B.C. -- Police say the search continues for an Alberta couple who were in a small plane believed to have gone down in southeastern British Columbia.

RCMP Cpl. Dan Moskaluk says pilot 28-year-old Dominic Neron and 31-year-old passenger Ashley Bourgeault were flying from Penticton, B.C., to Edmonton on Saturday when the single-engine aircraft vanished.

He says Penticton RCMP are helping the Victoria Joint Search Co-ordination Centre in the search for the missing couple and plane.

Rescue centre spokeswoman Katelyn Moores said earlier this week that the search area had been narrowed to a region 18 kilometres outside Revelstoke.

She said the grid was refined based on more complete information from radar and the cellphone tower that picked up a signal from the pilot's phone at about the same time the plane was reported missing.

Heavy snowfall, low clouds and densely treed terrain has made the search effort more difficult.