An investigation has been launched after three packages containing explosives were found near major transport hubs in London.
The Metropolitan Police said the "small improvised explosive devices" found in A4 postal bags at Heathrow Airport, London City Airport and Waterloo station were "capable of igniting a small fire when opened".
Irish police have also joined the investigation as the Heathrow and Waterloo packages had Republic of Ireland stamps on them, with Met's Counter Terrorism Command treating it as a "linked series".
All locations were evacuated and no injuries reported, local media said.

164 confirmed dead after two major earthquakes strike Venezuela
Europeans told to protect themselves as deadly heatwave takes its toll
Trump asks Congress for more funds to fight Iran, defying rebuke on war powers
Magnitude 6.9 quake strikes Japan's northeast, no tsunami warning
US, Iran at odds on nuclear inspections, frozen assets in deal to end war
