Related by context. Frequent words. (Click for all words.) 60 sniffer dogs 59 metal detectors 48 bomb disposal 48 metal detector 46 explosives 44 cordoned off 44 plainclothes officers 44 cadaver dogs 44 uniformed officers 44 Bomb Squad 44 frisking 43 X ray machines 42 Secret Service agents 42 heightened alert 42 riot gear 42 patrolled 42 Secret Service 41 protective suits 41 surveillance cameras 41 sharpshooters 41 plainclothes 41 SWAT 41 patrolling 40 heavily armed 40 screeners 39 hazardous material 39 Hazmat 39 pat downs 39 patrols 39 specially trained 39 frisk 38 hazmat 38 precaution 38 cordon 38 frisked 38 plain clothes 38 checkpoints 38 hazardous materials 38 searched 38 subway stations 38 X ray machine 38 FBI agents 38 entrances 37 booby trapped 37 escorted 37 commandos 37 uniformed 37 decontaminated 37 combed 37 security 37 TSA 37 beefed 37 Explosives 37 marshals 36 lockdown 36 canine 36 subways 36 body scanners 36 airports 35 contraband 35 National Guardsmen 35 Heavily armed 35 bloodhound 35 checked luggage 35 evacuated 35 water cannons 35 decontamination 35 firetrucks 34 wands 34 escorts 34 searches 34 combing 34 helicopters 34 scanners 34 armored vehicles 34 concourses 34 Security 34 canines 34 law enforcement 34 Uniformed 34 protective gear 34 bomb 34 detectors 34 sheriff deputies 33 thorough inspection 33 motorcade 33 assault rifles 33 parade route 33 dogs 33 dirty bomb 33 aerial surveillance 33 pepper spray 33 backhoes 33 officers 33 cordons 33 bullhorns 32 subway station 32 armored 32 flashing lights 32 X rayed 32 guards