Explosions rocked two Russian air bases hundreds of miles from the Ukrainian border on Monday morning, Russian media reported.

Driving the news: Russia's Defense Ministry on Monday said it shot down Ukrainian drones that had attacked military airfields in Russia's Saratov and Ryazan regions, according to state news agency RIA Novosti.

• Russian forces say they intercepted the drones, but the explosions killed three military technical personnel and injured four others, in addition to slightly damaging two aircraft.
• Ukraine has not claimed responsibility for the explosions. Other explosions have occurred within Russian territory, though those were much closer to the Ukrainian border.

State of play: The Engels air base houses strategic bombers that have previously been used to launch strikes on Ukraine and are capable of carrying nuclear weapons, the Wall Street Journal reported.

• The Ryazan air base is a hub for long-range flight tankers that can refuel bombers while in the air, per AP.

The big picture: Russia launched a fresh wave of missile strikes across Ukraine on Monday, continuing attacks on critical infrastructure as the war stretches into winter.

• "The enemy is again attacking the territory of Ukraine with missiles," Kyrylo Tymoshenko, the deputy head of the president's office, wrote in a Telegram post.
• Russian strikes in the Zaporizhzhia region killed two people and injured three others, Tymoshenko wrote on Telegram. Several private houses were destroyed, he added.
• The cities of Odesa, Cherkasy and Kryvyi Rih also reported explosions. In Odesa, a missile strike left the city without water after cutting the power supply to pumping stations, AP reported.
• "Unfortunately, there are already hits on energy infrastructure facilities and related emergency power outages," Ukraine's electric utility, Ukrenergo, wrote in a Facebook post Monday.

Editor's note: This article has been updated with new details throughout.