Several trains were stopped in the southern part of Russia’s Voronezh Region on Thursday after minor damage to a railway track was discovered, regional Governor Alexander Gusev confirmed.

“Several trains have been stopped on the railway section in the south of the Voronezh Region. The driver of one of them noticed minor damage to the tracks,” Gusev wrote on Telegram. He added that no casualties had been reported and operational services were determining the cause.

FSB: Explosion occurred moments before train arrival

Later in the day, Russia’s Federal Security Service (FSB) announced that the damage was caused by the detonation of an explosive device just before a train passed through the area.

“The FSB of Russia states that this morning, as a result of the detonation of an explosive device immediately before the passage of a train, a railway track in the Voronezh Region was damaged,” the agency said in an official statement.

The quick actions of the train driver and crew prevented a potential disaster. According to the FSB, they noticed the track damage in time and applied emergency braking, preventing harm to the train and passengers.

Authorities are now inspecting the scene and gathering evidence. The FSB said there is sufficient preliminary evidence to open a criminal case under the charge of terrorism.

Further details are expected as the investigation progresses.

Kremlin confirms Putin told Trump Russia will respond to Kiev’s airfield attacks

In a related context, the Kremlin has confirmed that Russian President Vladimir Putin informed US President Donald Trump that Moscow would respond to Ukraine’s recent attacks on Russian airfields.

Kremlin spokesman Dmitry Peskov stated Thursday that the nature and timing of the response would be left to the Russian military.

"The military will decide how and when the response will be appropriate," Peskov said during a press briefing.

In detail, Ukraine targeted four of Russia’s military airfields in Siberia and the far north in an operation using 117 unmanned aerial vehicles launched from containers close to the targets, codenamed “Spider’s Web”.

Peskov also clarified that while both leaders agreed that a future meeting is necessary, no formal arrangements have been made yet. “There is no agreement on a meeting,” he noted, “but there is a common understanding that proper preparation is required.”

The Kremlin described the Putin–Trump phone call as "constructive and necessary," with both leaders discussing multiple pressing issues. Sanctions were reportedly not on the agenda.

Bridge collapses and train derailments in western Russia spark terrorism probe

Three days earlier, explosions caused two railway bridges to collapse in western Russia, derailing two trains and resulting in seven deaths and dozens of injuries. The first incident occurred in the Bryansk region on Saturday, when a bridge collapsed on top of a passenger train, killing the driver and injuring multiple passengers. Hours later, a second bridge in the nearby Kursk region collapsed beneath a freight train, causing a derailment and fire but no casualties.

Russia’s Investigative Committee initially said explosions caused the collapses, but later edited its statement to remove the word “explosions". The incidents are being investigated as potential acts of terrorism.

In a separate claim, Ukraine’s military intelligence (GUR) reported that a Russian military freight train transporting fuel and food was blown up en route to Crimea. While GUR did not claim direct responsibility for the attack or connect it to the bridge collapses, it stated that the route to Crimea and the Zaporizhzhia region had been "destroyed".

Officials in Bryansk declared three days of mourning starting Monday for the victims. Meanwhile, further damage to railway infrastructure was reported in the region as investigators and emergency crews cleared debris from the crash sites.