Two soldiers may have been exposed to mustard gas while defusing an unexploded bomb on a North Gower beach in Wales.
A shell found on the beach in Whiteford Sands, Swansea, was disabled by Army Explosive Ordnance Disposal (EOD) personnel on Thursday. Two members of the team later developed skin symptoms similar to those associated with exposure to sulphur mustard - mustard gas.
They were treated in hospital and are now recovering at home, Wales Online reported.
It does not normally cause any health problems at the time of exposure, but symptoms can develop from between four to six hours later or up to three days after, depending on the level of exposure.
Symptoms can include eye and skin irritation, eye reddening, skin blistering, skin burns, sinus pain, coughing, fever, headache, sore throat, hoarse voice and nausea.
Experts from the Ministry of Defence believe a small amount of mustard gas may have been released when the shell was detonated.
A section of the beach was cordoned off on Monday and the area has been decontaminated but the incident control team has not yet confirmed that the beach is safe.
Warning signs are in place to keep members of the public away from the affected area.
Huw Brunt, a consultant in environmental health protection for the National Public Health Service for Wales (NPHS), said: "We are aware of the potential health risks associated with exposure to sulphur mustard exposure, but consider the risks to be low in this instance.
"Nevertheless, if visitors to the affected area of beach between these dates have developed symptoms or have any health-related concerns, they should contact their GP as soon as possible for advice."