Transcript for US cities increase security after Manchester attack

We've seen the effects of what happened in Manchester in times square. Security being stepped up here and across the country. To our senior justice correspondent Pierre Thomas with the latest. Good morning, Pierre. Reporter: George, good morning. Today homeland security officials say Americans can expect to see increased security in and around public places and events as officials take additional precautions. New yorkers, governors last night put out a statement directing state law enforcement officials to step up security patrols at high-profile locations around New York including airport, bridges, tums and mass transit systems. This was a cold-blooded and calculated attempt and officials I spoke to said the careful choice of a target speaks to direct involvement by I.C.E. Or a senior Al Qaeda leaders but authorities warn it's early and can't say for certain until a full investigation of a suicide bomber and get a sense of the explosive device use sfwld partly targeting young children and families, thanks very much,

This transcript has been automatically generated and may not be 100% accurate.