Dissident republicans intended to detonate a bomb at around the time the UK withdrew from the EU on January 31, police have said.
PSNI temporary assistant chief constable George Clarke said the bomb was a "viable device" and he believed it had been planted by the Continuity IRA (CIRA). It was found ealier this week on a lorry in Silverwood Industrial Estate in Lurgan after police had initially been told on the evening of January 31 that it was on a trailer in Belfast docks, bound for a midnight ferry crossing to Scotland, according to ACC Clarke.
The senior officer said the call had been made to a media organisation and while there was no midnight departure there was an earlier crossing and police carried out searches although nothing was found.
On Monday February 3 a second call was made to the same media outlet with "substantially more detail", he said.
"It gave us the detail of a commercial haulage company and it indicated that the device had been left on a vehicle on a trailer connected to that company and the intention had been for that device to explode on Friday evening at around the time the United Kingdom left the European Union."
Mr Clarke declined to be drawn when asked whether the device would have had the capacity to sink the ferry.
"I am not going to get into a discussion about the engineering of the device but I will make a very simply point - anybody who plants a device in a public place is reckless to the consequences of their actions and of the potential to kill or seriously injure people in that area," he said.
"This is an incredibly reckless activity."
Police have now stepped up their presence, both uniformed and undercover, at ports in Northern Ireland amid fears of another attack.
Stena Line declined to comment due to the live police investigation.
ACC Clarke said the lorry carrying the bomb had not left the commercial yard in Lurgan but if it had it would have exposed the public to "huge levels of risk".
"These bombs are made by terrorists. They are made to a standard which cannot guarantee any form of safety.
"Once that device had left that yard, if it had of done, it was exposing people on the public road, at a busy time, and at busy places, to huge levels of risk.
"These people are absolutely callous and reckless in what they have done."
Earlier today Detective Superintendent Sean Wright, from the PSNI's terrorism investigation unit, said police had first received a report on the evening of Friday January 31 "that an explosive device was in a lorry in Belfast docks".
"That report informed police that the lorry was due to travel by ferry to Scotland. Based on this information police conducted checks of the docks area and worked with the ferry company, Belfast Harbour authorities and Police Scotland to try to locate that device. After thorough checks nothing was found. The ferry sailed and arrived safely in Scotland."
DS Wright added: "It is clear from the information available to police that dissident republicans deliberately and recklessly attached an explosive device to a heavy goods vehicle in the full knowledge and expectation that it would put the driver of that vehicle, road users and the wider public at serious risk of injury and possible death."
Read more:Dissident republicans blamed after bomb found in Lurgan
