Staff at the Calgary Co-op's Oakridge Centre location found pins in a few packaged deli cheese items and a package of flatbread. (CBC)

More metal pins have been found in cheese and bread in a southwest Calgary Co-op store.

Staff found the objects in a few packaged deli cheese items and a package of flatbread in the Oakridge Centre location of the grocery chain before the store opened Thursday.

This isn't the first time food tampering has been discovered at the store, located at Southland Drive and 24th Street S.W. On Jan. 18 and Feb. 17, pins were found in bakery items, cheese, juices and some bulk food.

The store has increased security and carried out regular searches of its products since the first incident, said spokeswoman Sara Boutron. She wouldn't give details about security improvements, citing the police investigation.

Customers are asked to check items they've purchased from the Oakridge Centre store and can return any product they're unsure about for a full refund.

"Customers have been returning products, either that they found something in their product or they think that something could have happened to it," Boutron said, adding she is not aware of anybody being hurt.

Loyal shopper concerned

Longtime Calgary Co-op shopper Juanita Broderick said the incidents are making her nervous.

Pins have been found in bakery items, cheese, juices and some bulk food. (CBC)

"I had planned on going in to get a lot of groceries but I was just too scared to pick up anything other than things that I know won't be tampered with. And I think this is utterly ridiculous. The co-op's got to do something for their members."

But Gordie Rowan, who has shopped at the store for 30 years, said he would never think about shopping elsewhere.

"Why would you change? They give us good service, a good store, the staff's nice," he said.

Boutron said customers have been "very supportive" of the store.

"This is their centre. This is where they shop. It's part of their community and they don't understand why someone would do this," she said.

Police, who are investigating, said last month they were closing in on suspects. At the time, police said the tampering seemed designed to disrupt business rather than harm customers.