According to the UK Defence journal, Typhoon aircraft operating ten miles north of Mosul delivered a Paveway attack on a bunker and tunnel network, destroying their targets.
A number of secondary explosions ensued, most likely from stored ammunition. The next day, Typhoons operating over the same area north of Mosul conducted successful attacks with Paveway IVs on a further three tunnels.
An excavator preparing defences nearby was also destroyed.
Operation Shader is the operational code name given to the British participation in the ongoing military intervention against ISIL.
The operation began in Iraq on the 26th of September 2014, following a formal request for assistance by the Iraqi government.