The two incidents took place on Saturday evening and Sunday morning, respectively. In the first case, a bridge fell in front of a moving passenger train in Bryansk Region. The second incident took place in Kursk Region when a railway bridge collapsed under a moving freight train. In total, seven people died and 113 were injured.

In a statement on Tuesday, the Investigative Committee said that Moscow is treating both sabotage acts as “terrorist attacks.”

“It is clear that the terrorists, acting under the direction of the Kiev regime, planned the attacks with maximum precision to ensure that hundreds of civilians would be affected,” a spokeswoman said.

The committee added that investigators had recovered explosive device fragments and other physical evidence from the scene and had questioned witnesses, injured passengers, and rail railroad employees.

Earlier, Russian business daily Kommersant reported that investigators believe the saboteurs were likely using a US-made C-4 explosive device. They reportedly came to this conclusion after retrieving a 10kg bomb that did not detonate.

Both attacks came shortly before the second round of Russia-Ukraine talks in Istanbul and amid a drastic increase in Kiev’s drone raids into Russia, which Moscow says are aimed at derailing the peace process.

The negotiations in Türkiye brought no breakthroughs, but the sides agreed to conduct the largest prisoner exchange to date and indicated that direct contact would continue. Moscow and Kiev have also exchanged memorandums containing drastically different visions for ending the conflict.

Russia insists, among other things, that Kiev withdraw all troops from the regions that have joined the country in public referendums, agree to bloc neutrality, disband nationalist armed groups, and limit its military capabilities. Ukraine, however, continues to oppose the neutrality principle, wants to have an opportunity to deploy foreign troops on its soil, and is against recognizing any territorial losses.

“God loves the Trinity, and the SBU always brings what is conceived to the end and never repeats itself,” SBU Chief Vasyl Malyuk said in a statement posted on social media.

“Previously, we struck the Crimean Bridge in 2022 and 2023. So today we continued this tradition underwater,” he added.

The SBU announced that the operation “lasted for several months, with agents mining the “supports of this illegal construction.”

Constructed after Russia’s illegal occupation of Crimea in 2014, the Crimean Bridge is a critical supply and transport route for Russian forces to the occupied Ukrainian territories.

“And today, without inflicting any civilian casualties, the first explosive was activated at 4:44 a.m.,” the SBU said.

Underwater supports of the bridge’s piers were severely damaged at the bottom as 1,100 kilograms of explosives in TNT equivalent were detonated, according to the statement.

The operation, which follows the SBU’s mass drone strike against Russia’s strategic aviation on June 1, was personally supervised by the agency’s chief, Vasyl Maliuk.

A claimed “agent of Ukrainian intelligence services” has been detained in Crimea, Russia’s Federal Security Service said later on June 3, accusing the detainee of producing a “powerful explosive.”

The bridge suffered significant damage during two previous Ukrainian attacks in October 2022 and July 2023, though neither managed to take the bridge out of commission.

The construction of the bridge, also known as the Kerch Bridge, holds a significant symbolic value for Russia. The $4 billion project was a political statement designed to affirm the Kremlin’s illegal 2014 annexation of Crimea, as the peninsula is not connected by land to Russia.