This browser does not support the Video element.
SAN FRANCISCO (KTVU) - Local and federal law enforcement agencies are teaming up this week to protect public transit for the Super Bowl.
There are extra police presence at bay area airports, train stations, and ferry terminals.
Bart riders will notice officers boarding trains with bomb-sniffing police dogs.
Homeland Security is also monitoring the air, for signs of potential chemical and biological attacks. Agents have
installed metal boxes atop 6-foot-poles in San Francisco's financial district. The Associated Press reports that these boxes act as "air sniffers" meant to spot dangerous chemicals or biological agents.
The Energy Department's National Nuclear Security Administration is also flying low-altitude helicopter patterns up and down the coast, testing for spikes in radiation levels that could indicate a dirty bomb.
These flights are being monitored through an FBI command center.