Moscow said that Ukraine had fired six American ATACMS ballistic missiles, six British Storm Shadow cruise missiles and at least 146 drones at Russia and vowed not to leave the attack unanswered, Reuters reports.
Kiev first fired ATACMS and British Storm Shadow missiles at Russia last year and Moscow responded on November 21 by firing a new hypersonic medium-range ballistic missile, known as the "Oreshnik", at Ukraine.
The Russian Defense Ministry said it had shot down all Western missiles launched from Ukraine in the Bryansk region, as well as 146 drones outside the war zone. Two more Storm Shadows missiles were shot down over the Black Sea.
"The actions of the Kiev regime, supported by its Western curators, will not go unanswered," the Defense Ministry stressed.
In November, President Vladimir Putin said that the war in Ukraine was escalating into a global conflict after the United States and Britain allowed Ukraine to launch their missiles deep into Russian territory.
US President-elect Donald Trump has called for a ceasefire and negotiations to quickly end the war, which calls into question Washington's long-term support for Ukraine.
Russian invasion of Ukraine in 2022 caused tens of thousands of deaths, displaced millions and triggered the biggest crisis in relations between Moscow and the West since the Cuban Missile Crisis of 1962.
The drone attack on Russia was one of the largest ever.
Roman Busargin, governor of the Saratov region, about 720 km southeast of Moscow, said the cities of Saratov and Engels on the banks of the Volga River had been subjected to a massive drone attack and two industrial sites had been damaged. Schools have switched to remote learning.
Ukraine attacked the same region last week and said it had hit an oil depot serving an air base for Russian nuclear bombers. The attack caused a huge fire that took five days to extinguish.
An ammunition depot containing guided bombs and missiles at the Engels air base in Russia's Saratov region was hit, as well as other targets, a source from the Security Service of Ukraine reported today.
The attack caused a large fire at the Aleksinskoye chemical plant in the Tula region and a fire at the Saratov oil refinery, while the Bryansk chemical plant was also hit.
The source said there were subsequent detonations at the Bryansk chemical plant, as well as a large fire. The operation was carried out by the SBU and the Ukrainian Defense Forces.
Flight restrictions were imposed at the airports in Kazan, Saratov, Penza, Ulyanovsk and Nizhnekamsk.