A New York Police helicopter circles Liberty Island after a bomb threat made by an anonymous 911 caller forced the evacuation of hundreds of tourists Friday from the Statue of Liberty, but a thorough sweep of the landmark by investigators turned up no explosives.

Statue Cruises, which operates the ferries that carry tourists to the Statue of Liberty and Ellis Island, said it safely evacuated 2,700 people from the island. It offered them refunds and help getting back any items left behind.

Service to the island was to resume this morning.