The IRA has claimed responsibility for a series of letter bombs sent to addresses in England and Scotland last week, the Met Police has confirmed.

A man claiming to represent a dissident Republican organisation - also known as the New IRA - contacted a media organisation in Northern Ireland on Monday and used a recognised codeword to make the claim.

Four devices were identified last week at transport hubs in London and at Glasgow University, although the person claiming responsibility stated that five devices had been sent.

Police said relevant businesses and sectors had been warned to remain vigilant for potential devices.

In a statement to the Irish News, the caller said three of the devices had been sent to "commercial targets", while the two others had been sent to British army recruitment centres.

The group said a device discovered at Glasgow University had been intended for a British army recruitment officer who worked there.