A man slipped past security screeners into the boarding area at Oakland International Airport on Tuesday morning, causing long lines outside terminals and delaying flights as authorities searched for the intruder.
Law enforcement officers with bomb-sniffing dogs combed the airport's two terminals for the man, who entered the restricted section of the main terminal through an exit lane next to a security checkpoint, airport officials said.
Search teams also boarded every plane preparing to depart to determine if the man was on board, airport spokeswoman Rosemary Barnes said.
Authorities declined to say whether the man had been caught or if the security breach was intentional.
Long lines of passengers waiting to board flights snaked down sidewalks outside both terminals as security checkpoints were closed down for more than an hour during the search. Passengers who had already passed through security were allowed to remain inside, said Nico Melendez, a spokesman for the Transportation Security Administration.
"We were able to do a sweep of the two terminals and make a determination that an evacuation was not necessary," Melendez said.
Departing flights were held until all passengers delayed by the search had passed through security and boarded, resulting in flight delays of up to three hours, Barnes said.
"No one will miss their flight here out of Oakland this morning," Barnes said.
Passengers arriving around the time of the 9 a.m. breach were stranded on their planes for about an hour.
The incident likely snarled at least 2,000 departing and arriving passengers, Barnes said.
Both terminals were reopened after authorities determined the man didn't pose a threat, Melendez said.
Security forces are on heightened alert throughout the San Francisco Bay Area as an estimated 250,000 fans converge on and near San Francisco's AT&T Park for the All-Star Game festivities.
Kevin Hallinan, head of security for Major League Baseball, said last week that the level of security at the ballpark is higher than the World Series in 2002, a year after the terrorist attacks on New York and Washington.
Roads around ballpark, the Embarcadero and the piers will be closed until midnight Tuesday, after the midseason classic ends. The Coast Guard will put canine enforcement teams on ferries headed to the game.
Planes will be restricted from flying within three nautical miles of the ballpark, a Federal Aviation Administration spokesman said. And FBI-led SWAT teams will be stationed nearby, said Special Agent Joseph Schadler.