Turkeys tested positive for bird flu at nine more Indiana farms near the location where authorities first confirmed a strain different from the one that ravaged the U.S. poultry industry last summer, Indiana authorities said on Saturday.

Farmers began euthanizing turkeys at the new farms even before final results of whether the birds were infected with the H7N8 strain, said Denise Derrer, spokeswoman for the Indiana State Board of Animal Health. Final results are expected soon from a government laboratory in Ames, Iowa.

The nine farms are located in Dubois County, about 70 miles from Louisville, Kentucky. All of the new infections are within a quarantine area set up around the first farm and that area has been expanded to four neighboring Indiana counties — Martin, Orange, Crawford and Daviess.

Confirmation of new bird flu cases alarmed industry officials after the rapid spread of the H5N2 virus last year led to the deaths of about 48 million turkeys and chickens, and drove egg prices higher.

"We are very concerned and trying to figure out strategies to contain it," Derrer said of the outbreak.

She said officials are trying to determine how many birds will have to be euthanized at the nine farms. The state animal health board website said one of the farms had 12,000 turkeys and another 23,500. It did not give figures for the other seven. All 60,000 turkeys at the first farm have been euthanized.

It isn't clear whether the mild winter weather played a role in the current outbreak of the virus, state and federal officials said. The H7N8 virus has not yet been found in wild birds, suggesting that the virus could have developed in wild birds that spent the winter in southern Indiana, USDA spokeswoman Andrea McNally said Friday.

Research has shown that wild birds' northern migration introduced the H5N2 virus, which began to accelerate from farm to farm last spring.

While the H7N8 strain is highly contagious for birds, the USDA said no human infections from the viral strain have been detected.

Indiana's poultry industry brings in $2.5 billion a year, Derrer said, adding that the state leads the country in duck production, is No. 3 in egg production and fourth in turkeys. Dubois County is Indiana's top poultry producer with 1.4 million turkeys, she said.

The Indiana farm where the strain was first found is associated with Farbest Farms, a company that produces about 15 million turkeys a year and has contract growers in Indiana, Illinois and Kentucky. Derrer declined to say if the new infections also were on farms linked to the company.

Indiana Gov. Mike Pence met Saturday with state and local officials at an incident command center set up since the outbreak. Pence emphasized in a statement that the poultry industry is vital to Indiana and authorities are "bringing all necessary resources to deal with this situation."