Details have been murky over the number of tourists affected and the possible source of the methanol-laced drinks.

Simone White was enjoying a holiday with friends in Laos last week when she accepted a free shot from a bar. The 28-year-old British lawyer is one of six people to have died in a suspected mass methanol poisoning in the backpacking town of Vang Vieng.

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.