The dogs can sniff out many different types of explosives.
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Dozens of federal and local law enforcement agencies have heightened security in preparation for Sunday’s Super Bowl, limiting access to New Jersey’s MetLife Stadium, bringing in sniffer dogs and beefing up measures for mass transit in light of recent suicide bombings in Russia.

The Transportation Security Administration said it has added about two dozen dogs to monitor passengers coming in and out of the airport around the Super Bowl.