Ukraine staged a dramatic series of strikes across Russia, deploying drones hidden in trucks deep inside the country to hit strategic airfields as far away as eastern Siberia. Around the same time, Moscow launched one of its longest drone and missile attacks against Kyiv, escalating tensions ahead of crucial peace talks this week. More than 40 Russian aircraft, including the Tu-95 and Tu-22 M3 long-range bombers capable of deploying conventional and nuclear weapons as well as the A-50, are reported to have been damaged in the operation on Sunday, an official in Ukraine's Security Service said on condition of anonymity as the details are not public. Ukraine's Security Service chief Vasyl Malyuk led the operation and losses are assessed to be at least 2 billion, the person said.

"The Ukrainian army launched a drone strike on a civilian car carrying Izvestia's freelance correspondent Alexander Martemyanov," the news outlet reported on its Telegram channel. "The car was located far from the line of contact." The vehicle was returning from covering shelling in the Russian-held city of Gorlivka when it was hit, Russia's state RIA news agency said. Two RIA journalists were wounded in the attack, the agency added. Russian Foreign Ministry spokeswoman Maria Zakharova called the incident "deliberate murder".

State Department spokesman Ned Price will hold a briefing Tuesday afternoon after drones struck inside Russia's border with Ukraine in the second day of attacks. The briefing is scheduled to begin at 1:45 p.m. ET. Watch the event live in the player above. Ukrainian officials did not formally confirm carrying out drone strikes inside Russia, and they have maintained ambiguity over previous high-profile attacks. But Ukrainian presidential adviser Mikhail Podolyak taunted Moscow in comments on Twitter, and Britain's Defense Ministry said Russia was likely to consider the attacks on Russian bases more than 500 kilometers (300 miles) from the border with Ukraine as "some of the most strategically significant failures of force protection since its invasion of Ukraine."