Breaking News Emails

Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.
 / Updated 

Seven suspicious packages sent to army recruitment offices in England contained "viable devices" bearing the hallmarks of "Northern Ireland terrorism," a spokesperson from Prime Minister David Cameron's office said on Thursday.

“Seven suspect packages have been identified as containing small, crude, but potentially viable devices bearing the hallmarks of Northern Ireland related terrorism,” the Downing Street spokesperson said in a statement.

“These have now been safely dealt with by the police and bomb disposal units.”

Explosives experts in Britain were investigating a suspected letter bomb campaign after several suspicious packages were mailed to military recruitment centers.

Bomb disposal teams were called to six different British Army careers centers across England over the past three days, police said.

One further suspect package was found Thursday in a vehicle at a U.K. military base used by the U.S. Air Force, but a U.S. official said there was no information to connect it to the other incidents.

The packages “have now been safely dealt with by the police and bomb disposal units,” the Downing Street spokesperson said.

“Guidance has been issued to staff at all military establishments and Royal Mail asking them to be extra vigilant and to look out for any suspect packages and the screening procedures for mail to Armed Forces Careers offices is being reviewed,” they added.

Reuters contributed to this report.