More details from everythingedl.
Update 2: See “Man arrested after Facebook bomb threat to Birmingham Central Mosque”, Birmingham Mail, 12 December 2011
Update 3: See “Second man bailed following bomb threats”, West Midlands Police press release, 13 December 2012
The latter case concerns “two separate online threats made against a local temple and a second unspecified target”. Police “don’t believe this and the threat made against Birmingham Central Mosque on Sunday are connected”. Apart from the fact that the second casereportedly also involves an EDL member, that is.