Airports and other border crossings in the U.S. were put on high alert Saturday, after the failed terrorist attack in central London Friday. New York City mayor Michael Bloomberg has canceled all police leave and increased security at public institutions, as well as at synagogues, in light of information supplied by Homeland Security.

Three suspects were arrested in Glasgow, Scotland, when they rammed their car through a checkpoint at the city's airport. The three either set fire to their car or otherwise exploded it, causing damage to the airport terminal.

Police did not announce the identities of the suspects in the Glasgow incident, but terrorism by Al Qaeda cells in Britain is suspected.