A Russian cargo vessel, the Ursa Major, sank following a series of unexplained explosions and may have been transporting two nuclear reactors intended for North Korea, as reported by CNN on Tuesday.

The incident involving the Ursa Major has remained enigmatic since December 23, 2024. Findings from a Spanish-led probe suggest possible military action to thwart Russia's transfer of nuclear technology to Pyongyang.

Intense military presence near the wreck has fueled speculation about its payload and intended route. Public flight records show U.S. nuclear detection planes, dubbed 'sniffer' aircraft, examining the site twice over the last year. The Ursa Major belonged to Russia's sanctions-evading 'Ghost Fleet' and was en route from St. Petersburg to Vladivostok through the Mediterranean, per its official manifest.

The manifest listed cargo as two oversized 'manhole covers,' 129 empty containers, and two Liebherr cranes. It was accompanied by two Russian Navy vessels, the Ivan Gren and Aleksandr Otrakovsky, according to a recent Spanish government statement.

As the Ursa Major suddenly slowed, Spanish rescuers contacted the crew to assess any distress. The next day, it deviated sharply from course and signaled for aid, reporting three blasts on the starboard side near the engine room. Two crew members died, stranding the ship.

Spanish forces rescued the 14 survivors before a escorting Russian warship instructed vessels to maintain a 2-nautical-mile distance and demanded the crew's return. Spain prioritized rescue and inquiry efforts into the blasts.

CNN reports the Ursa Major appeared stable and salvageable initially. At 9:50 p.m., the Ivan Gren launched red flares overhead, followed by four explosions registered by Spain's seismic network. By 11:10 p.m., the vessel had submerged completely.

Unusual Developments Around the Wreckage

Post-rescue, Spanish officials took the Russian survivors to Cartagena for police questioning. The crew and captain hesitated to reveal details about the cargo or itinerary, per the probe.

Captain Igor Vladimirovich Anisimov faced questions about the 'manhole covers' on the manifest, as noted in the Spanish report.

He admitted they were parts of two submarine-style nuclear reactors, though lacking fuel, according to his account - unverified at this stage.

Investigators determined these 'covers' were probably reactor casings for nuclear propulsion, akin to submarine models.

Anisimov suspected the journey was set to divert to Rason in North Korea to offload the reactor components.

A week later, Russian warships revisited the site for five days, after which four additional blasts occurred, likely to obliterate seafloor remnants, a probe insider told CNN.

CNN highlighted U.S. scrutiny: Elite 'nuke sniffer' planes from Nebraska's Offutt Air Force Base circled the wreck on August 28, 2025, and February 6, 2026.

Base spokesman Kris Pierce explained to CNN that these aircraft aid in nuclear debris gathering and evaluation.

He declined to elaborate on flight paths, results, or collaborations.

Analysts note a prior similar flight a year earlier, hinting at standard U.S. monitoring routines.

Probe sources said Anisimov recalled no blast on December 22 during the slowdown, but explosions the next day near engines claimed two unrecovered lives.

Spanish findings point to a possible Barracuda supercavitating torpedo - a weapon held by only the U.S., Russia, Iran, and select NATO allies.