A bomb has been sent to the Belfast offices of Democratic Unionist Party deputy leader Mr Peter Robinson, he revealed tonight.
A parcel believed to be packed with explosives and ball-bearings was opened by his daughter as she dealt with mail. It failed to detonate.
A second parcel-type device was also delivered to the headquarters of the Northern Ireland Policing Board in the city's Clarendon Docks area.
It is believed to have been addressed to Mr Alex Attwood, one of the nationalist SDLP representatives on the body which holds Chief Constable Hugh Orde to account, and was described as primitive by security sources.
A Board spokeswoman said: "I cannot confirm or deny who it was sent to." Army experts were called in to defuse the parcel bomb at Mr Robinson's headquarters.
Although the East Belfast MP was unclear about who had targeted him, he hit out at the bombers for launching an indiscriminate attack.
He said: "It's particularly despicable because anybody who sends that kind of device would know that it would not be opened by the member of parliament himself but by a member of his staff.
"For someone to attempt to kill a member of staff because they disagree with me indicates the kind of mind we are dealing with."
The alert began when Mr Robinson's daughter Rebecca was sorting through post at the constituency offices on Belmont Avenue today.
When she opened a jiffy-type bag and discovered suspicious contents, Mr Robinson's bodyguard urged her to take it out and leave it in a nearby entry.
A Police Service of Northern Ireland spokeswoman confirmed that a viable device had been dealt with at Belmont Avenue.
PA