The leaders of some of Europe's most secretive police units and FBI members met in Dublin recently to exchange information on "intervention" tactics to counter organised criminal and terrorist activity.
The conference, under the codename Project Oisin, was held in the Grand Hotel, Malahide, and was attended by police units from several European countries and the United States.
Although there was little obvious security, the conference hall was carefully screened. The proceedings passed off without notice while a major cross-Border education conference took place in the main conference complex.
It is understood the security conference was arranged so that police specialist units could share information about training and experience in confronting terrorist and organised criminals.
Part of the conference covered maritime intervention, particularly against drug smugglers, in which the gardai and the Naval Service have experience.
A paper on maritime intervention was given by a member of the Garda's Emergency Response Unit (ERU) who was involved in some of the operations to intercept drug-smuggling vessels.
Representatives from the FBI gave a lecture on hostage rescue.
One of the main concerns of police and military intervention forces is to avoid "collateral" casualties in ending sieges. Some forces, such as the French paramilitary GSG9, have made major advances in techniques for ending sieges without loss of innocent people's lives.
The London Metropolitan police force's anti-terrorist unit, SO19, which has seen action repeatedly against the IRA over the past decade gave a talk on their new intervention tactics.
The Garda side was represented by members of the ERU and senior Special Branch figures.