Russia's daily COVID-19 death toll passed 900 for the first time on Wednesday.
It recorded 929 fatalities - a new record that comes amid the country's low vaccination rate and the government's reluctance to tighten restrictions.
The previous record, of 895 deaths, was registered on Tuesday.
Health workers have blamed the resurgence on the reluctance of young people to get the jab.
"Young people don't care that much about their health, because they think they are young, strong, and healthy. So they don't get vaccinated," said Sergey Babikov, head of an intensive care unit in the southwestern region of Stavropol.
"I didn't get vaccinated. Like everyone, I was postponing it again and again. And then it [catching the virus] happened in one second," a patient said.
Russia, with a population of 146 million people, currently has Europe's highest death toll from the pandemic, standing at 210,000 people.
Oleg Kolpakov, the head of a cemetery in the Stavropol city of Nevinnomyssk, said the number of burials was more than 50% higher than in pre-pandemic times.
"We used to bury 120 to 130 people per month. Now we bury more than 200. Young people, students, workers, strong men, and people who were just working yesterday and who contracted the virus in a week or two. And then we meet them here with their relatives," Kolpakov said.
Officials have said that the vast majority of people in hospital are unvaccinated, and President Vladimir Putin has repeatedly urged Russians to get the jab.
Russia was the first country to create a coronavirus vaccine, but recent independent polls have shown that many Russians are sceptical of the Russian-made vaccines.
Critics have principally blamed the low uptake on a botched vaccine rollout, mixed messages the authorities have been sending about the outbreak, and the non-distribution of vaccines made abroad.
Doctors also suggested that the popularity of COVID-19 antibody tests in Russia contributes to the low vaccination numbers.
Russian Deputy Prime Minister Tatiana Golikova, who manages the national coronavirus response, warned of a difficult period ahead.
"We have a rise in morbidity and I want to ask you to be careful," Golikova said. She added that despite the new daily record of COVID-19 deaths, the Russian government was reluctant to introduce nationwide restrictions that could hurt the economy.
Restaurants, bars, and nightclubs remain open, though some regions have announced they will reimpose rules requiring people to show proof of vaccination.