According to local news sources, explosions have occurred at two air bases in Russia.

Monday, according to the Russian state-run news agencies TASS and RIA Novosti, an explosion rocked an airfield near the city of Ryazan, southeast of Moscow, and a large explosion was reported at another Russian military air base in the Saratov region, located approximately 600 kilometers east of Ukraine.

TASS reported that three people were killed and six were injured in the explosion in Ryazan, while RIA Novosti cited an emergency services source as saying an aircraft was damaged in the explosion that occurred after a fuel truck caught fire.

At approximately 6 a.m. local time on Monday, social media videos appeared to show a large explosion at the Engels-2 air base in Saratov.

"Two TU-95 aircraft were reportedly damaged in a drone attack on an air base in Russian Engels, Saratov region," tweeted Anton Gerashchenko, advisor to the Ukrainian minister of internal affairs.

"The Engels airbase is one of the launch sites for Russian aircraft that fire rockets at Ukraine," Gerashchenko wrote.

The governor of Saratov, Roman Busargin, issued a statement urging residents to remain calm, without providing further details about the reported explosion.

"I wish to state that no extraordinary events have occurred in the city's residential areas," he wrote. "There is no cause for alarm. No damage to civilian infrastructure has been reported. Security agencies are reviewing information about events at military installations."

According to him, law enforcement agencies are investigating "incidents at military facilities."

Dmitry Peskov, a spokesman for the Kremlin, told reporters on Monday that he was unaware of the causes of the explosions.