Dozens of suspected drones have been spotted flying over states on the East Coast of the United States, sparking concern from local officials.

Staten Island Borough President Vito Fossella said the drones, often seen flying at night, have been spotted hovering over critical infrastructure, including Port Liberty New York near the Goethals Bridge, the Verrazzano-Narrows Bridge and Fort Wadsworth, one of the oldest military installations in the country.

The White House, Pentagon and Homeland Security (DHS) have all said there's no evidence that the reported drone appearances state-wide pose a threat to national security. "It appears that many of the reported sightings are actually manned aircraft, operating lawfully", the FBI and DHS have said in a statement.