The National Park Service said Monday that sharpshooters killed 20 white-tailed deer in Rock Creek Park during a three-night operation to reduce the number of the animals roaming the park.

The federal government said that the government gunmen, who used lead-free ammunition, had killed 20 deer without incident while the park was closed for three nights.

The park service ordered the operation as the number of deer in the park soared in recent decades, a trend that officials said was threatening the long-term livelihood of its plants.

The plan was the subject of passionate protests, but the authorities said they plan to stage another such culling in the fall. The park service is hoping to cut the number of deer per square mile from 70 to 15-20.

The government said it will donate venison to area food banks and homeless shelters.