The makeshift explosives posted to 2 London airports and its busiest train station have stamps suggesting they came from Ireland

Dan Kitwood/Getty Images

Terminal 5 at London's Heathrow Airport and a stamp issued by Ireland's An Post in February 2017 that says "Love Éire" or "Love Ireland."

• Irish police are assisting their London counterparts in a terror investigation after packages containing makeshift bombs were sent to two of the city's airports and its busiest train station.
• Photos of the packages show the packages have Irish stamps and a return address in Dublin.
• No one was hurt and transport systems remained running after the packages were found at London Heathrow Airport, London City Airport, and Waterloo Station on Tuesday.

Three packages of makeshift explosives that were posted to two major airports and the busiest train station in London on Tuesday appear to have stamps suggesting they came from Ireland.

No one was hurt and transport systems were not interrupted after packages containing "small improvised explosive devices" were reported at London Heathrow Airport, London City Airport, and Waterloo Station on Tuesday.

London's Metropolitan Police said on Tuesday that the devices seemed "capable of igniting an initially small fire when opened" and were sent in "A4-sized white postal bags containing yellow Jiffy bags."

Read more: 2 London airports and its busiest train station were sent makeshift bombs at the same time

Ireland's police force, the Garda Síochána, confirmed to Business Insider that it is helping the Met Police with its terror investigation.

Images obtained by Sky News and MailOnline showed that the packages had Irish stamps and listed a return address in Dublin, the Irish capital.

Stephen Murphy, Ireland Correspondent for Sky News, shared an image of what he said was the parcel sent to Heathrow Airport:

Both the London Metropolitan Police and the Garda Síochána declined to comment on the images.

The stamp appears to be one issued by An Post - Ireland's postal service - for Valentine's Day in February 2018, as seen below. It says "Love Éire," which translates to "Love Ireland."

An Post

A postage stamp issued by Ireland's postage service in February 2018 matches the one on photos of packages obtained by Sky News.

The package addressed to London's Waterloo Station had a return address to Bus Éireann, Ireland's national bus service, Irish national broadcaster RTÉ reported.

A Bus Éireann spokeswoman told RTÉ that British police had not been in contact, saying: "Bus Éireann are currently not aware of this and we have no further comment."

David Videcette, a former counterterror detective with the Met Police, told MailOnline that the writing on the envelope "looks like a child's writing or done with someone's non-dominant hand."

"Someone wants this to look like it's come from the Republic of Ireland," he added.

The Met Police said on Tuesday that they were keeping an "open mind" regarding the motive behind the packages. It said that it was treating the incidents as "linked." No arrests have been made as of Tuesday night.

Experts have warned of the potential for increased dissident activity between Ireland and Northern Ireland, which is technically part of the UK, due to Brexit and the potential erection of a so-called "hard border" between the two XXXXX if the UK leaves the EU without a deal.

An Irish police source told The Guardian that investigators are not jumping to the conclusion that the parcels were sent to further the cause of Irish Republican terrorists.

But sources told the Mail Online and The Telegraph that such activity could not be discounted.