Investigations in to the devices used in the explosions are ongoing and enquiries are being sought in order to verify the claim.

The claim was made on behalf of an entity known as the Irish Republican Army (IRA), who have claimed responsibility for planting explosive devices at the University of Glasgow, including three transport hubs in London, according to police sources used by the Scottish Sun News.

Later, the UK Metropolitan Police and Police Scotland confirmed they were aware of the claim, but stated they continued probing the devices and the claim itself.

"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 police added.

The claim was received on Monday 11 March by a media outlet in Northern Ireland outlet using a recognised codeword.

Roughly eight buildings were evacuated at the university after a suspicious package was discovered around 10:45am on 6 March.

A controlled explosion was conducted after facilities were evacuated at the city's West End, Metropolitan Police said. Counterterrorism officers have also linked similar packages sent to three busy travel hubs in London earlier the same week.

A police spokesperson said in a Tuesday press release: "Police Scotland and the Metropolitan Police 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."

"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."

— Metropolitan Police (@metpoliceuk) March 12, 2019

"We continue to urge the public to remain vigilant and report anything suspicious to police," the spokesperson added.

Met Counterterrorism detectives are investigating the three packages in London, whilst Police Scotland are investigating the incident at University of Glasgow. Both agencies are sharing intelligence to assist their inquiries.

But only four of the five planted devices have been found, as the group have claimed responsibility for sending five devices, authorities said. Police are informing businesses and sectors in the UK to remain vigilant and report suspicious packages to police, with similar advice being previously sent to UK military forces.

READ MORE: Edinburgh's Main Street Evacuated Over Suspicious Package — Reports

Police had discovered suspicious packages around 9:55am at The Compass Centre near Heathrow Airport, Nelson Road, and Hounslow, Metropolitan Police said. The package had been opened by staff at the building, setting off the device. No one was injured and flights were unaffected by the incident.

British Transport Police were alerted at Waterloo station around 11:40, and bomb diffusing officers neutralised the device, with no injuries being reported. Similar incidences were reported at the City Aviation House, Royal Docs, Newham, with police conducting staff evacuations and diffusing devices. Flights were also unaffected, police said.