A massive Russian navy submarine was armed with long-range nuclear missiles when it caught fire while undergoing repairs at a northern dock late last year, a respected weekly reported on Monday.

In a cover article entitled "Russia Narrowly Avoided a Second Chernobyl," the Vlast weekly said the crew of the Yekaterinburg had ignored regular practice and docked in Murmansk for service work while still carrying weapons.

"The presence of weapons at the time of the fire was confirmed to Vlast by several different sources within the Russian navy and Northern Fleet command," the magazine said.

The report did not include quotes from officials and conceded that navy submarines usually remove their arsenals before docking for repairs.

But it said several unusual factors about the December fire suggested the vessel was carrying 16 long-range nuclear missile with four warheads each as well as torpedoes, some of which may have been nuclear-tipped.

It said that a few days after the fire was put out, the vessel was towed to a secret military base that stores a part of the Northern Fleet's nuclear arsenal.

Vlast said there was no reason for the vessel, which will be decommissioned for several months while it undergoes repairs, to be at the weapons depot except to remove its stock of nuclear-tipped missiles.

The weekly also said that vessels that need repairs between missions often go in for quick fixes fully armed because the loading and unloading procedure is so time-consuming.

There was no comment to the report from Russian naval or other defence officials.

The 11,400-tonne Delta IV class Yekaterinburg was commissioned in 1985 and along with five other such vessels forms the backbone of Russia's sea-based nuclear defences.