UPDATE, 6:00pm: ABC7 Chicago and NBC Newswire are reporting that the "all clear" has been given. KENS5.co reports that the FBI is continuing its investigation.
UPDATE, 5:46pm: San Antonio Police Chief Bill McManus has told WOAI that while both terminals have been cleared, the "all clear" has yet to be given.
UPDATE, 5:06pm: Airport spokesman Rich Johnson confirmed to The Huffington Post that the airport is working on getting buses onto the tarmac to keep evacuated passengers cool. Johnson said that some 20 flights have so far been affected as a result of the scare. The lobby of Terminal B has been reopened, Terminal A remains closed. Johnson confirmed that there had been "three hits" on vehicles in a parking lot and are being investigated at this time.
UPDATE, 4:47pm: Airport spokesman Rich Johnson told MyFoxla.com, "It is warm out here right now, so we're trying to get some water to some of the people. Inbound planes are being allowed to land, they're just being held in the tarmac area at the current time." Johnson added that emergency crews have completed a sweep of Terminal B and people are being allowed back inside; the sweep of Terminal A, which is the larger of the two, is ongoing.
PREVIOUSLY: San Antonio's International Airport was evacuated Wednesday afternoon following an apparent bomb threat, Fox 6 reports.
KENS5.com reports that both terminals were evacuated and passengers are standing on the tarmac. A "very specific threat" was called in around 2pm CST, WAFF.com reports.
My San Antonio reports that roughly 1,000 people have been evacuated from the terminal. 25 area buses have been sent to the airport to help with the evacuation.
Fox San Antonio reports that all flights are on hold at the moment.
Head to KSAT for a live stream from the airport.
This is developing, more to come...