Two people needed treatment in hospital for minor burns after making the find. Mustard gas was used as a weapon during World War One and outlawed by the Geneva Protocol of 1925.

Two people suffered minor burns and three people, arrested on suspicion of possessing a noxious substance, remain under investigation. The area was cordoned off after some of the mustard gas ...

Dermatological examination revealed degree 2a burns ... of mustard, including allyl isothiocyanate, are strong skin irritants and vasodilators and are used as rubefacients or as tear gas.

Officers hoped the vomiting, suffocation and burns caused by poison gases would ... But the most infamous - and deadliest - was mustard gas, in reality an oily vapour first used by the Germans ...