Four men have been charged after police recovered an armour-piercing mortar during searches in Lurgan.
They were arrested last week by police investigating dissident republican activity in the area.
Three men, aged 22, 24 and 46, have been charged with targeting a former member of the security forces in the Craigavon area.
A fourth, aged 22, has been charged with the attempted murder of police officers.
He is also charged with possessing explosives with intent to endanger life on 31 August in Lurgan.
The men will appear at Craigavon Magistrates Court on Tuesday.
A 22-year-old man arrested last Thursday as part of the same investigation was released unconditionally over the weekend.
Police, who described the device as “potentially lethal”, said it had been recovered during a large-scale police operation.
Assistant Chief Constable Will Kerr said: “We are relieved and delighted to have taken an extremely dangerous explosive device out of circulation.
“Our experience of these devices in Northern Ireland has been that they have been used to try to kill police officers.”
ACC Kerr said the device had been located in a derelict house in a residential area close to people’s homes.
“Those responsible have absolutely no regard for the local community, or indeed any community,” he said.
“I would also like to thank the local community for their patience and understanding during the disruption of search activity in recent days. Our primary aim has been community safety.”