The Statue of Liberty has been evacuated as a precaution after a bomb threat, forcing hundreds of tourists to be herded off the New York island.

An anonymous caller made the threat late on Friday morning, "stating they were going to blow up the Statue of Liberty," the National Park Service said in a statement on Friday.

Federal police, including two canine units, investigated and the dogs found "an area of interest" in a locker area at the statue's base, the agency said. Law enforcement then decided to evacuate the island.

Nothing harmful was found in the lockers, according to New York Police Department spokesman Steve David, but the bomb squad continued sweeping the area on Friday afternoon as a precaution.

Statue Cruises, which operates the ferries that carry tourists to the Statue of Liberty National Monument and Ellis Island, said officials found a suspicious package at Liberty Island.

The company was postponing all service to the island until the investigation was completed, said Mike Burke, its chief operating officer and vice president.

Eric Gustafson, of Worchester, Massachusetts, was on Liberty Island with his wife and son. They were about to enter the building for the tour when park rangers ushered "everyone to the flagpole" and then told them they had to leave.

"They didn't give us a reason for it. The communication was lacking," he said. About 90 minutes later, they were back in Manhattan.

They later saw Twitter accounts about a suspicious package.

"We weren't nervous. It was mostly just frustrating," he said, adding that the evacuation was very orderly.

Other tourists said they were taken off boats while trying to leave nearby Ellis Island, then those vessels then were used to evacuate Liberty Island.

Karen Mason, 68, of Cincinnati, Ohio, said they had just boarded a boat at Ellis Island at 12:40 pm. "All of a sudden, they said 'Disembark, disembark, disembark. We have to evacuate the boat."

She said she didn't feel like she was in any danger. "But we saw helicopters and we knew something was going on," she said.

Source: Agencies