WORCESTER (CBS) – Several puppies stolen from an animal shelter in Sterling have been found.

Four of the nine stolen pups were recovered after police tracked down a tip. Sylvia Ortiz, 22 of Worcester, was arrested late Thursday at her home and charged with receiving stolen property.

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“We’re not sure if she was involved in the actual break-in or whether somebody else just gave the puppies to her,” shelter manager Melissa Snitzer said. “She claims that she woke up in the morning and the puppies were in her apartment.”

Two more puppies were returned to the shelter Friday morning. A seventh puppy was discovered Friday afternoon by two women who were walking their own dog in Worcester. Two puppies are still missing.

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Shelter Manager Melissa Snitzer Speaks With Lana Jones.

View: Photos of stolen pups

Employees of Animal Shelter Inc. found a kennel door kicked in when they arrived at work Thursday morning.

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All of the recovered puppies are being treated for kennel cough. Snitzer said they are getting plenty of calls from people interested in adopting them.