Moscow's international airports were temporarily closed due to safety concerns after air defense forces intercepted multiple Ukrainian drones.
The Russian health ministry registered the first vaccine against COVID-19, named Sputnik V, on August 11.
Russia's newest completed World Cup stadium, the Otkrytie Arena, in Moscow, was opened by the country's President Vladimir Putin on Wednesday.
Investigators are looking into a possible terror attack as well as keeping an open mind to the motive of the subway blast, a Kremlin leader said.