VANG VIENG, Laos — The Lao government on Saturday officially acknowledged the mass poisoning that killed at least six tourists, vowing to bring those responsible to justice.

After that, two Australian teenagers and a British woman died of suspected methanol poisoning consuming contaminated alcohol in Laos. An American and two Danes also died, although the exact causes of their deaths have not been released. A New Zealander was also sick.

In a brief statement to the media, the Lao government said it was “deeply saddened by the loss of life of foreign tourists” in the city of Vang Vieng and offered condolences to the families of the victims.

“The Lao PDR government has conducted investigations to find the causes of the incident and bring the perpetrators to justice in accordance with the law,” the statement said.

Laos is a one-party communist state with no organized opposition and the government controls information. In this case, officials have released almost no details. Police said they had detained several people but declined to provide further information.

Details were unclear on the number of tourists affected and the possible source of the methanol drinks.

Methanol is sometimes added to mixed drinks at unrecognizable bars as a cheaper alternative to ethanol, but can cause serious poisoning or death. It’s also a byproduct of poorly distilled homebrew and could have inadvertently found its way into bar drinks.

The US State Department issued a health alert for citizens traveling to Laos on Friday, warning of “suspected methanol poisoning in Vang Vieng, possibly through consumption of alcoholic beverages containing methanol”, following similar alerts in other countries of whose citizens were involved.

Nineteen-year-old Australians Bianca Jones and Holly Bowles died in Thai hospitals on Thursday and Friday respectively after being evacuated from Laos for emergency treatment. Thai authorities confirmed that Jones died of “swelling of the brain due to high levels of methanol found in her system”.

Both were found ill in their room at Nana Backpacker Hostel on November 13 after failing to check out as planned.

Britain’s Foreign Office named 28-year-old Briton Simone White as another victim.

Landlocked Laos is one of the poorest nations in Southeast Asia and a popular tourist destination. Vang Vieng is especially popular with tourists looking for parties and adventure sports.