A school caretaker has been charged over a series of letter bombs sent to addresses in England and Wales.
The devices exploded when they were opened
Miles Cooper, 27, has been charged with seven offences under the Explosive Substances Act and with five offences against the person.
He was arrested on Monday in Cherry Hinton, Cambridge, in connection with seven devices posted over three weeks.
Nine people were hurt in the attacks in London, Swansea, the West Midlands, Berkshire, Kent and Oxfordshire.
Mr Cooper is due to appear at Banbury Magistrates' Court in Oxfordshire on Friday.
Anton Setchell, the Association of Chief Police Officers' national co-ordinator for domestic extremism, said Mr Cooper had been charged "in connection with a series of improvised explosive devices that were sent through the post to companies and organisations".
Mr Setchell said the letter bomb investigation, Operation Hansel, was "progressing well" and would continue for many weeks.
He added: "I am now satisfied that there are no other postal packages connected to this inquiry that will present a danger to the public."
Paul Harrison, from the Crown Prosecution Service, said the service had been assessing all available evidence in order to decide on charges "at the earliest possible opportunity".
There was sufficient evidence to charge Mr Cooper with 12 offences contrary to the Explosive Substances Act and the Offences Against the Person Act, he said.
He added: "We will continue to keep this case under constant review as it develops."
Seven of the 12 charges relate to the seven letter bombs, while the other five charges relate to the people who were injured after opening them.
Four workers were injured when a parcel bomb exploded in the post room at the Driver and Vehicle Licensing Agency's main centre in Swansea earlier this month.
During the previous week, two men had suffered blast wounds to their hands and upper bodies in a "small explosion" at accountancy company Vantis in Wokingham, Berkshire, and a woman had been hurt in an explosion at the Capita office building in Victoria Street, Victoria, London.
The previous four bombs were sent to a private home in Folkestone, Kent, two companies in Oxfordshire and the Forensic Science Service in Chelmsley Wood, near Birmingham.