The news report said there were Irish postage stamps on the package.
Yes, which whilst not proving anything, does perhaps suggest a dissident Irish Republican connection.
Reports that the Irish police are working with the Metropolitan police, again proves nothing but does suggest a possible/suspected connection.
Bombs sent by post were a popular tactic of the IRA, but don't seem to be favoured by Islamic extremist terrorists.
Anti airport extremists seem unlikely to send a bomb to a railway station.
A disgruntled ex-employee seems unlikely to attack airports AND a railway station.
Simple criminal extortion would normally be confined to one business or to closely related businesses.