A drilling rig with 67 people fell into the icy Sea of Okhotsk off Russia's far eastern island of Sakhalin on Sunday while it was being towed amid rough waters. The accident killed four people and 50 were lost at sea.

The crew of the icebreaker Magadan and tugboat Neftegaz-55 plus two helicopters rescued 14 workers of the Kolskaya jack-up rig after they fell into the water.

The Magadan and the Neftegaz-55 were towing the Kolskaya, which is owned by Russian offshore exploration firm Arktikmorneftegazrazvedka (AMNGR), from Kamchatka to Sakhalin Island when its gas pipes were damaged by waves and took in water causing the rig to keel to its side at 12:45 p.m.. Within 20 minutes, the rig fell into the 1,042-metre deep water giving people aboard little time to board inflatable life rafts.

A search and rescue operation was launched to find the missing people about 200 kilometres off the coast of Sakhalin.

Russia's federal Investigative Committee has started investigating the accident. It appears that the AMNGR violated safety rules by towing the rig in the middle of a storm and is liable to criminal charges.

The 69-metre-long and 80-metre-wide Kolskaya was built in 1985 in Finland and was used in shelf exploration on the Okhotsk Sea.

The Russian Emergency Situations Ministry said search and rescue operations will continue Monday despite strong winds and four-metre high waves.

The Kolskaya jack-up drilling rig.