An explosion derails a freight prepare in a Russian border space, in line with a neighborhood governor.

An explosion derailed a freight prepare in Russia’s Bryansk area on Monday, in line with the native governor and the Russian railways firm, the newest in a spate of obvious assaults to hit the realm bordering Ukraine.

Photos and movies circulating on social media confirmed a big hearth burning and a prepare tilted askew, with not less than one carriage mendacity on its facet.

The governor of the Bryansk area, Aleksandr V. Bogomaz, blamed an “unidentified explosive device,” saying in a put up on the Telegram messaging app that there have been no casualties. He didn’t say who was accountable, and Ukraine didn’t declare to have been behind the blast, though Kyiv typically maintains a coverage of strategic ambiguity about strikes on Russian territory.

The Russian railways firm stated in a press release that “an intrusion by unauthorized individuals” derailed the prepare, which set the locomotive on hearth. The incident blocked visitors on the rail line, the assertion stated.

In neighboring Belarus, the Ministry of Transport and Communications issued a press release saying that the blast concerned one in all its freight trains, the official Belta news company reported. Eight vehicles of the 78-car prepare derailed, it stated, however the locomotive crew was not injured.

Rybar, an influential pro-war Russian army weblog that posted one of many movies, stated on the Telegram messaging app that prepare vehicles carrying oil merchandise and lumber have been mendacity on their facet.

The blast got here a day after Mr. Bogomaz stated 4 individuals within the area have been killed by Ukrainian shelling from throughout the border.

Russia has used territories near Ukraine — together with the Bryansk area, alongside Ukraine’s northern border — to stage assaults, hearth rockets, launch air assaults and mount different assaults all through the 14-month-old battle. The Ukrainian authorities has expressed rising concern that Moscow is utilizing the Bryansk area to launch drone assaults.

Officials in Kyiv have stated they reserve the proper to strike targets inside Russia that they declare are used to assault Ukrainian cities and cities, however have promised to not use weapons provided by Western allies for such assaults, since allies worry Moscow might view that as a provocation.

In March, Ukrainian particular forces stated that that they had destroyed an unmanned remark tower in Russia’s Bryansk area utilizing a drone strike, a uncommon public acknowledgment of a cross-border assault that underscored Kyiv’s rising willingness to immediately strike Russian territory.

That got here days after a short armed incursion right into a village in Bryansk by partisans claiming to struggle for Ukraine, a uncommon raid inside Russia that prompted President Vladimir V. Putin to cancel a visit and convene an emergency assembly of his safety council.

Marc Santora and Neil MacFarquhar contributed reporting.