The U.S. Food and Drug Administration said today that it tested retail samples of milk and other dairy products in 17 states for viable bird flu virus, providing further details about the locations of the previously disclosed tests.

The regulator said it collected 297 samples at retail locations in 17 states between April 18-22, but the retail samples represented products made at 132 processing locations in 38 states.

“Even if a sample was collected in one particular state, the milk in a consumer package could have come from cows on several farms located in several states, pasteurized in a different state from where the milk was produced, and available for purchase in yet another state,” the agency said in its statement.

The U.S. has confirmed bird flu in dairy cattle in nine states since late March.

The FDA had said on May 10 that no live virus was found in retail milk samples. It has also said that pasteurized milk is safe to drink but has cautioned against consuming raw milk.

Scientists, however, have said they believe the outbreak is more widespread based on the FDA’s findings that showed about 20% of retail milk samples contained remnants of the H5N1 virus.

The samples included cottage cheese, cream, and half and half, which is equal parts milk and cream, sour cream and yoghurt, in addition to milk.