Security suddenly boosted at Amsterdam's Schipol Airport

Amsterdam's Schiphol Airport has suddenly boosted its security in a move authorities there have linked to the "national threat level," snarling traffic as military police check cars coming to drop passengers off.

An employee working at the airport told The Associated Press the move followed an unspecified threat. She spoke on condition of anonymity because she was not authorized to speak to the media.

Schiphol has not reported any delayed flights but authorities said Saturday that extra security would be "visible and noticeable."

Saturday is one of the busiest days of the year for Schiphol airport, as many people start their summer holidays and the Dutch Olympic delegation is set to fly out to Rio de Janeiro for the 2016 Summer Olympics.