At least 41 residents of the Siberian city of Irkutsk have died after drinking scented bath oil in a desperate search for an alcoholic high in one of the deadliest cases of its kind in years, Russian investigators say.
Use of counterfeit or surrogate alcohol is rife in Russia's regions, where two years of economic pain have pushed more people below the poverty line.
Russian media reported that the victims were poor residents of Irkutsk, a city around 4000km east of Moscow.
The case underlines how hard up a large swath of the population is despite Moscow's growing profile and clout on the global stage.
"It is a terrible tragedy," Kremlin spokesman Dmitry Peskov told reporters. "This type of problem is well-known and the president has been informed. Measures must be taken."
Russia's Investigative Committee sent a group of experienced investigators from Moscow, while Russian news agencies said the Mayor of Irkutsk had declared a state of emergency and temporarily banned the sale of all liquids containing spirits not meant for human consumption.
"According to our latest data 41 of 57 people who were hospitalised after drinking the liquid have died," investigators said in a statement. "More than 2000 units of the liquid have been confiscated with an overall volume of 500 litres."
Among liquids that have been used as a substitute for alcoholic drinks are perfume, after-shave, anti-freeze and window cleaner.
Alexei Navalny, a Kremlin critic who wants to challenge Vladimir Putin for the presidency in 2018, said the case had garnered wide attention because so many people had died at the same time.
Hundreds of people, he said, died unremarked every day in unrelated cases for the same reason.
"The problem... for Russia and its national security is roughly a thousand times more important than Syria, Aleppo, Ukraine and Trump put together," said Navalny, blaming poverty and corruption for the sale of such toxic surrogates.
"Every year... [such concoctions] kill more people than have been killed in terrorist attacks in Russia's entire history."
Investigators, who opened a criminal case into the poisonings, said they had detained two people suspected of distributing the deadly bath oil.
The bath oil contained methylated spirit, they said, a toxic substance found in cleaning materials and paint stripper.