MOSCOW – A Russian icebreaker labored Monday through howling winds and heavy snow as it tried to reach icebound ships in the Sea of Okhotsk where more than 500 seamen are trapped.

Three of the vessels have been trapped since Friday in ice estimated to be two meters (6 1/2 feet) thick. The state news agency RIA Novosti said two more ships became stuck on Monday.

The Sea of Okhotsk is an arm of the northern Pacific to the west of Russia's Kamchatka Peninsula.

A statement from the Transport Ministry said there was no immediate danger to the crew on the three ships stuck since last week, who have sufficient food and water. The Ministry said an icebreaker was expected to reach their vicinity early Tuesday.

RIA Novosti cited a local coast guard official as saying winds on the sea were up to 30 meters per second (more than 65 mph).

The three ships that have been trapped since Friday — a fishing vessel, a refrigerated freighter and a scientific research ship — are in a tight convoy. The two others are about 20 nautical miles (35 kilometers) away.