A group calling itself the IRA says it was behind the parcel bombs sent to three London transport hubs and the University of Glasgow last week, according to police.
Officers say the group claimed five devices were sent but only four have been found so far.
Police Scotland and the Metropolitan Police have said the claim was received by a Northern Ireland media outlet using a recognised codeword.
The forces said in a joint statement it was allegedly made “on behalf of the IRA”.
Source: Sky News