A nuclear-powered Soviet submarine that appears to have sunk after it caught fire off the coast of Norway was probably carrying atomic weapons, Norwegian Defense Minister Johan Joergen Holst said Saturday.

"There is reason to believe that the boat has sunk," he told state radio. "We know it was nuclear-powered and probably had nuclear weapons on board."In Washington, Pentagon officials were quoted as saying up to 12 Soviet sailors died aboard the "Mike" class attack submarine built to carry a crew of about 95.

"It is clearly a very serious accident," Holst said.

"A number of the crew, we don't know how many, took to the boats and have been picked up by Soviet ships that went to the scene," he added.

"Mike" submarines are 361 feet long and capable of speeds up to 38 knots. They are built to hunt other ships and can carry both anti-ship torpedoes and land-attack cruise missiles with a range of up to 1,200 miles, according to the authoritative Jane's Fighting Ships publication. Those missiles can be armed with conventional or nuclear warheads.

Col Gullow Gjeseth of Norway's Defense Command said a Norwegian observation plane flew to the area of the accident at about 6 p.m. (10 a.m. MST). "We saw no submarine, which indicates that it had either already sunk or was in the process of sinking," he said.

The plane's crew saw two rubber dinghies, one of which had people in it.

Asked how Norwegian authorities had received their information, he told state radio: "I would rather not go into that."

A second observation plane flew over the area, about 125 miles west southwest of Bear Island, which lies between the Spitzbergen archipelago and the Norwegian mainland. It had not yet returned, Gjeseth said.

Soviet ships and aircraft rushed to the area, he added.

Gjeseth said it was too early to say whether there was any danger of a radioactive leak from the reactors that power the submarine.

"It depends on what happened. Reactors on board such submarines are built to withstand a great deal," he said.

"It is clearly a very serious accident," Defense Minister Holst said, adding that NATO member Norway would be seeking information from Soviet authorities as soon as possible. There was no immediate comment from Moscow.

Johan Baali, director of Norway's State Radiation Technology Board, said a fire on board could damage a reactor sufficiently to cause radioactive leaks.

"It's too early to say, but in such a case, it could be a substantial amount (of radiation)," he told state radio.

Holst told the radio the water was 6,500 feet deep in the international waters where the submarine appeared to have sunk.

Arne Finne, spokesman for northern Norway's main rescue center in the town of Bodoe, said Norway had offered assistance to the Soviet Arctic port of Murmansk. No reply had yet been received.

The Soviet Union has 10 atomic-powered submarines in its huge northern fleet, based around Murmansk on the Kola peninsula, according to Western defense experts. Norway and the Soviet Union share an Arctic border in the area.

Holst said that if the ship had sunk, it was unlikely that it could withstand water pressure at the depths in the area but important parts of the reactors would probably be able to do so.

"The vessel would break up. . . but we think that the critical parts of the reactor can withstand much greater pressure."

He said a special government crisis unit was meeting through the night to assess the danger of radiation. "It is difficult to say, but first indications are that the danger is not that great."

"A number of the crew, we don't know how many, took to the boats and have been picked up by Soviet ships that went to the scene," Holst said in a later radio interview.

ABC Television, quoting unnamed senior Pentagon officials, said as many as a dozen Soviet crewmen died in the accident. The officials said the rest of the crewmembers were rescued by Soviet ships and submarines before the submarine sank.

ABC said the vessel was a highly advanced prototype that was used to test Soviet weapon systems.

Former Navy Secretary John Lehman told the network that the submarine, launched in 1983, was the only one of its class in the Soviet navy.

The Pentagon officials quoted said the Bush administration would shortly contact the Soviet Union to see whether efforts were needed to prevent the possible spread of nuclear waste from the sunken submarine.

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(Chart)

Soviet submarine

"Mike" class

This single boat is probably a test vehicle for new design and and propulsion features

First deployed: 1983

Displacement, tons: 6,400 dived

Length: 360.8 feet

Width: 39.4 feet

Height: 29.5 feet

Torpedo tubes: Six 21 inch and 25.6 inch for torpedoes

Missiles: Can probable carry SS-N-15, SS-N-16 and 1,600 nautical mile range SS-N-21 missiles instead of torpedoes

Mines: Can lay up to 64 mines

Main machinery: Two nuclear reactors (probably liquid metal cooled)

Speed, knots: 38

Crew: Approximately 95

Source: "Jane's Fighting Ships"