Conservation officers have had to kill two of nearly 30 black bears that had been trained to wander the grounds of a B.C. marijuana grow-op.

Boundary Conservation Insp. Aaron Canuel says the two bears were destroyed because they repeatedly approached backyard decks in the southern B.C. community of Christina Lake, about 500 kilometres east of Vancouver.

The bears had been trained to eat dog food and were found as RCMP investigated the suspected marijuana grow-op in the Boundary region last year.

Efforts were made to wean the bears before they hibernated last fall and Canuel says officers have been keeping a close eye on the bruins since they woke up.

He says a late spring means it's taking longer for new food sources to sprout at higher elevations, but he's hoping the remaining bears will follow their noses and abandon urban areas when human handouts disappear.

Allen Piche pleaded guilty in March to feeding dangerous wildlife, an offence under the Wildlife Act; he and several others still face charges related to the grow-op.