(CNN)A "viable improvised explosive device" found in western Ireland is linked to an investigation into similar devices in London and Scotland, authorities said Friday.
Explosive device found in Ireland linked to those sent to UK, say London's Met Police
It was contained in a plastic envelope and found in a postal collection center in Limerick, Irish police said in a statement.
Irish police were alerted to a suspicious item shortly after 6 a.m. local time on Friday, authorities said. The army's bomb disposal team arrived at the An Post's collection center at 9:50 a.m. local time, where the package was found.
"On arrival a cordon was established and the building was evacuated for the duration of the operation. A viable improvised explosive device contained in a plastic envelope was identified and made safe," the Irish police statement said.
London's Metropolitan Police is cooperating with the Irish police on these investigations, both forces said.
"Whilst it is still early, from the images we've seen and from speaking to our counterparts in the Republic of Ireland, it appears that the package found in Limerick is linked to those sent to London and Glasgow on 5 and 6 March," Deputy Assistant Commissioner Dean Haydon said.
A group calling itself the IRA previously claimed responsibility for sending five packages containing improvised explosive devices to the UK earlier in March, but British police said they had only recovered four.
On March 5, three devices were sent to major London transport hubs -- Waterloo Station and offices at Heathrow and City Airports -- in what police said appeared to be part of a "linked series."
All the devices were judged to be viable, and the package sent to Heathrow Airport burst into flames after being opened by staff. Nobody was injured by the devices and no arrests have been made.
The packages were posted with Irish stamps and had return addresses in Dublin, prompting Irish police to join the investigation. The packages were all A4-sized white postal bags containing yellow padded bags, which were capable of igniting when opened.
Police Scotland confirmed that a controlled explosion was carried out on the package found at the University of Glasgow on March 6 as a precautionary measure.
The Metropolitan Police and Police Scotland said in a joint statement that the devices "bore similarities" to past packages "linked to dissident groups associated with Northern Ireland related terrorism," and that "officers were already looking at this as a line of enquiry."
The devices did not cause any injuries or damage.