The U.S., Australia and U.K. have issued warnings for travelers in Vang Vieng after several tourists died in a suspected methanol poisoning outbreak.

Six tourists, including Australians and a British woman, died in Laos, likely from methanol poisoning. The U.S. State Department warns travelers about this risk. The Laos government is investigating the incident and expressed condolences to the victims' families.

The NHS warns that as little as 4ml of methanol can cause hallucinations and blindness. Half an hour to two hours after consuming methanol symptoms include drowsiness, confusion and irritability. Later symptoms include dizziness, vomiting, severe abdominal pain and diarrhoea.