MURMANSK, Russia (AP) _ Workers at a shipyard in northern Russia have barred a recently repaired nuclear-powered submarine from sailing out to sea in a protest over unpaid back wages.

Workers in the naval yard in Polyarny have been guarding the submarine around the clock for three days to stop it from leaving, the ITAR-Tass news agency reported Thursday.

The blockade nearly led to a clash when some navy officers tried to bring a tugboat into the dock to tow the submarine out into the Barents Sea, the report said. The submarine's name and type were not given.

The protesting workers have not been paid since August.

The Russian armed forces and defense industry have long been plagued by a severe shortage of funding.

In recent months, there have been several power cutoffs to North Fleet bases because of debts to the power industry. One nearly resulted in a nuclear accident, when the safety system of a nuclear submarine's reactor collapsed from a lack of electricity.