VANG VIENG, Laos (AP) — Two Australian tourists are being treated in Thailand for suspected severe alcohol poisoning after consuming tainted drinks in neighboring Laos, Australian media reported Tuesday.

The two 19-year-old women were on a backpacking vacation in Laos when they became ill in the tourist town of Vang Vieng, The Age newspaper in the women’s hometown of Melbourne reported.

Duong Duc Toan, manager of the Nana Backpacker Hostel, said staff were told by other guests that the women were unwell after they failed to check out as planned on Nov. 13, and they arranged transport to a hospital for them.

He said that two days earlier the women had joined more than 100 other guests for free shots of Lao vodka offered by the hostel as a gesture of hospitality. He said no other guest reported any issue, adding that the women had then gone for a night out, returning in the early hours of the morning.

Australia’s Department of Foreign Affairs and Trade confirmed that it was providing consular assistance to two Australians and their families in Thailand but could not provide further information for privacy reasons.

“Our thoughts are with them at this deeply distressing time,” the office said.

They were then transported to Thailand and are being treated at hospitals in Bangkok and Udon Thani, The Age reported. Their parents have flown in to be with them.

It was not clear what the two drank, but methanol is sometimes used as the alcohol in mixed drinks at disreputable bars and can cause severe poisoning or death.

It was not immediately possible to verify reports that other tourists were also poisoned in the same incident.

Toan, the hostel manager, said he hoped the investigation would clear its name but for now the hostel has stopped giving free shots to its guests.