New York and New Jersey authorities say there've been no specific terror threats against the Super Bowl. But they're using a formidable combination of manpower and technology to secure the spectacle as a precaution.
The authorities outlined the efforts at a briefing on Wednesday in Manhattan.
Commissioner William Bratton said the New York Police Department is using extra officers, bomb-sniffing dogs and surveillance cameras to watch for trouble this week along the "Super Bowl Boulevard" street fair in Manhattan.
New Jersey state police will deploy up to 700 troopers at MetLife Stadium on Sunday when the Denver Broncos and the Seattle Seahawks prepare to face off.
A 24-hour federal command centre in New Jersey is monitoring domestic and international intelligence.
Authorities also are studying terror attacks before the Winter Olympics in Sochi for lessons on how to better protect mass transit.