At least 16 people died and dozens fell ill from drinking contaminated cider in the western Russian region of Ulyanovsk, its governor said on Monday.
"Sixteen people died" from drinking adulterated cider, governor Alexei Russkikh said.
Another 35 became ill, he said, and 19 of them were hospitalised in clinics across the region.
"Doctors are fighting for everyone's life," Russkikh added.
In an earlier Telegram post, Russkikh said people were poisoned after drinking "Mister Cider" produced in the Samara region.
He said "law enforcement officers are seizing these products in our region."
Russian authorities opened an investigation into the incident.
Russian media said the alcohol contained methanol, which is highly toxic.
Such cases are not uncommon in Russia, where cheap alcohol substitutes are a persistent problem, particularly in rural areas with very low standards of living.
In 2021, at least 34 people died from drinking bootleg liquor containing methanol, in two separate incidents.
In 2016 more than 60 people died in the Siberian city of Irkutsk after drinking bath essence containing methanol, a toxic substance used in anti-freeze.
bur/imm