COEYMANS, N.Y. -- Authorities say the 15 buffaloes that escaped from a farm have been shot and killed because they became a danger after crossing the New York State Thruway.

Three men hired by the farm were cleared to open fire Friday afternoon in a stream in woods in the town of Coeymans, about 10 miles south of the capital. CBS affiliate WRGB reports that the Albany County Sheriff's Office nor the Bethlehem Police Department were involved in the shooting on the animals.

A herd of buffalo cross a road, Friday, April 24, 2015, in Bethlehem, N.Y. About 15 of the animals got loose Thursday from a farm in the Rensselaer County town of Schodack, on the river's east bank a few miles southeast of Albany. AP Photo/Mike Groll

Police say the decision was made after experts agreed tranquilizers would not be effective and no portable corrals could hold the animals.

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"I just couldn't believe it, I was absolutely amazed," said one driver who had to pull over when he saw the herd.

Albany County Sheriff Craig Apple yells at a man who was shooting at a herd of buffalo on Friday, April 24, 2015, in Coeymans, N.Y. Mike Groll, AP

The Times Union reported that one of the men hired to shoot the animals appeared to have a heated exchange with Albany County Sheriff Craig Apple, who said he was concerned about the safety of people in the area. The man was taken into custody and later released, the Times Union reported.

Authorities say the animals escaped Thursday from a farm across the Hudson River in the Rensselaer County town of Schodack. The owner believes they swam across the river to the town of Bethlehem, where they wandered across a busy stretch of Interstate 87 and into neighboring Coeymans.

"The buffalo are wild animals, they're not tame animals," farm owner George Mesic told the Times Union.

CBS affiliate WRGB reports that the animals can move as fast as 40 miles per hour.