Authorities have given the all-clear at an American Airlines terminal that was shut down at John F. Kennedy Airport because of a suspicious bag.

A law enforcement source said the bag was left by a man who was screened and boarded a flight to San Francisco. He left the bag in the business class lounge, the source said.

The Transportation Security Administration says a bomb-sniffing dog conducting routine screening gave an alert about the bag, so a bomb squad checked it out.

Authorities closed the check-in desk, the screening checkpoint and the roadway to the terminal, as a precaution.

The first alert was at about 7:42 a.m., and the all-clear was given around 9:15 a.m.

 8:55AM EST: Port Authority police have shut down an American Airlines terminal at John F. Kennedy Airport as they investigate a suspicious package.

A bomb squad has been called in to investigate the package, officials said.

This story is developing. Check back for updates.

(Source: NBC New York)