State health officials warned consumers not to drink milk products from Whittier Farms in Shrewsbury, Mass. after two people died after consuming products contaminated with listeria bacteria.

The Department of Public Health has identified four cases of the listerioris. 2 of the victims have died. The cases occurred in June, October and two in November. The four cases involved three elderly residents and a pregnant woman from Worcester county.

DNA fingerprinting conducted by the State Laboratory Institute showed that the bacteria causing these infections came from a common source.

Whittier Farms has agreed to suspend operations and distribution until a source of contamination is identified.

Brand names produced at Whittier Dairy include Whittier, Schultz, Balance Rock, Spring Brook, and Maple.