A Russian nuclear submarine which caught fire during repairs in the Arctic in December had its nuclear-tipped missiles and other weapons on board, the newspaper Kommersant Vlast reported on Monday.

The Yekaterinburg submarine was being repaired in a dry dock outside the north-western city of Murmansk when wooden scaffolding next to it caught fire and the flames spread to the craft on December 29. Nobody was killed in the blaze which raged on for hours.

The Defense Ministry said all weapons had been unloaded before the vessel entered the dock at the Roslyakovo shipyard.

Officials also said there had been no radiation leak from the Yekaterinburg, the Delta-IV-class nuclear submarine.

But the newspaper Kommersant Vlast claimed on Monday the sub “was in the dock with torpedoes and missiles on board.”

The Yekaterinburg, launched in 1984, can carry 16 intercontinental ballistic missiles, each with four warheads, and 12 torpedoes.

“For almost an entire day, Russia was on the verge of the worst anthropogenic catastrophe since Chernobyl,” the paper said.

The explosion at a nuclear plant in Chernobyl in Ukraine in 1986 was the worst accident in the history of nuclear power.

Weapons are normally removed from docked nuclear subs but the final decision often lies with commanders, the paper said.

Unloading can take up to two weeks, which can delay scheduled maneuvers. This might result in disrupting Russia’s nuclear parity with the United States, it said.

The Yekaterinburg, or K-84, traveled to two missile depots in early January.

“The only meaning of this move would be to unload the missiles and torpedoes onboard the K-84,” Kommersant Vlast said.

The paper said it also had the evidence of “several independent sources in the leadership of the Navy and the Northern Fleet.”

The fire was the latest in a string of Russia’s naval accidents, the worst being the sinking of the Kursk submarine in 2000, which left 118 people dead.