Russia is blaming Ukraine for a large-scale airstrike that hit a luxury building in the city, about 1,000km (620 miles) from the border.
Russian President Vladimir Putin has vowed to retaliate later Ukrainian drones destroyed residential buildings in the city of Kazan in the Tatarstan region of Russia.
Putin said this via video link on Sunday when he spoke with the leader of Tatarstan at the opening ceremony of the road.
“Everyone, no matter how much they try to destroy, will face more destruction and will regret what they are trying to do to our country,” Putin said.
On Saturday morning, six Ukrainian planes hit residential buildings in Kazan and a seventh hit an industrial complex. No injuries were officially reported, with media reports indicating that three people were cut by broken glass.
Videos on Russian social media showed drones hitting a glass skyscraper and setting it on fire, although no injuries were reported as a result of the strike.
Kazan is more than 1,000km (600 miles) from the Ukrainian border. Although Ukraine has not claimed responsibility for the attack, it appears to be a response to Russia's military offensive against Kyiv.
Putin has previously threatened to target Kyiv with a hypersonic missile in response to Ukraine's attack on Russian territory.
Putin's threat comes as Russia has said new things on the battlefield in eastern Ukraine.
The Ministry of Defense said on Telegram that its troops “liberated” the villages of Lozova in the northeast of Kharkiv region and Krasnoye – known as Sontsivka in Ukraine.
The latter is close to the Kurakhove military base, which Russia is close to encircling and would be a major prize in Moscow's attempt to seize the entire Donetsk region.
Russia has accelerated its advance into eastern Ukraine in recent months, looking to secure as much territory as possible before US President-elect Donald Trump takes office in January.
Republicans have vowed to end the nearly three-year-old conflict, offering no concrete terms for an end to the war or a peace deal.
Moscow's military is said to have captured more than 190 Ukrainian villages this year, with Kyiv struggling to hold the line due to a lack of manpower and equipment.