Military official said the bomb was probably aimed at the fleeing Norwegian royal family.
Nearly 100 Norwegian addresses can be found in the Panama Papers database and authorities are offering a deal to those who step forward now.
Many Brits abroad have the right to vote on Britain's future in the EU. They should use it, David Lidington, British Europe Minister, writes for The Local.
Police said it's too early to speculate on the cause of the fire.