Russia on Friday set another grim record for daily coronavirus deaths for the fourth straight day, with 679 fatalities recorded, bringing the overall toll to 136,565.
The rise in cases remains significant as well, with 23,218 people testing positive for COVID-19 over the past day, bringing the tally to 5.5 million and active cases to 389,277.
Over the same period, recoveries topped 5.03 million, including 18,197 registered since yesterday.
In a statement, Russia's chief sanitary officer Anna Popova said that 10 of Russia’s 49 regions have seen a rise in cases.
Every new coronavirus strain is a little stronger than the previous one, Popova told the Moscow Urban Forum on Friday.
She predicted that new vaccines will be needed to immunize against the new strains.
The capital Moscow continues to lead with the spread of the virus, which officials have blamed on the new Delta strain, said Vice Mayor Anastasia Rakova.
"The situation with the coronavirus in Moscow remains tense. Now, according to all studies, a new Indian strain Delta is dominating the city. It has, in fact, ousted all previous strains," she said.
More measures were introduced to stem the rise, including mandatory isolation and PCR tests for people suffering from flu-like illness to break the chain of infection, she said.
Officials are preparing reserve capabilities for COVID-19 patients to prevent any crises in the healthcare system, Rakova added.
A lockdown is seen as the last resort, and will be introduced only if other efforts do not work, she said.
Over the past day, 6,893 cases were registered in Moscow, raising the overall count to 1.37 million and active cases to 179,113.
Over the same period, the virus claimed 112 lives, pushing the death toll to 22,668 while recoveries increased by 6,271 to 1.17 million.