Controlled explosions most likely equate to suspicious packages, plus apparently a tip came in -- not sure yet, what this will turn out to be as it still is "breaking news."
http://icbirmingham.icnetwork.co.uk/0100news/0100localnews/tm_objectid=15714617&method=full&siteid=50002&headline=city-force-on-high-state-of-alert--name_page.html
"City force on high state of alert"
Jul 8 2005