The Met Police has issued a statement.
A group calling itself the 'IRA' claimed responsibility for a number of explosive devices left at locations in London and Glasgow last week, the Met police have confirmed.
A4-sized white postal bags containing an improvised explosive device were left at Waterloo Station, Heathrow and London City Airport on Tuesday 5 March. The devices were capable of igniting a small fire when opened, police said.
The following day on 6 March a similar device was discovered at Glasgow University.
Buildings were evacuated and counter-terror police were called to the scene in each instance, with no injuries during the disposable of the devices.
The Met Police said in a statement: "The Metropolitan Police and Police Scotland are aware of the claim of responsibility for the devices that were received at three buildings in London and at the University of Glasgow on 5 and 6 March. The claim was received on Monday 11 March by a media outlet in Northern Ireland outlet using a recognised codeword.
"The claim was allegedly made on behalf of the ‘IRA’.
"The investigations into these devices continue and relevant enquiries are being made in relation to the claim that has been made.
"Given the packages received last week bore similarities to devices sent in the past which were linked to dissident groups associated with Northern Ireland-related terrorism, officers were already looking at this as a line of enquiry. However, we continue to keep an open mind and enquiries continue."
The force added: "Detectives from the Met's Counter Terrorism Command are leading the investigation into the three packages received in London, whilst Police Scotland, under direction from the Crown, is leading the investigation into the package received at the University of Glasgow.
"Both investigation teams are working closely together to share any information or intelligence that could assist their respective inquiries."
