Russian officials say search and rescue efforts have been called off for the night, leaving 49 crew members still missing after an oil drilling rig with 67 crew on board capsized and sank in icy waters off the Far East island of Sakhalin.

A regional emergency ministry spokesman told reporters that four crewmen were confirmed dead.

Authorities say 14 crew members were rescued from the Kolskoye platform. They are reported in serious condition.

The ministry said a tugboat was towing the oil drilling rig, when it ran into a storm 200 kilometers off the Kamchatka peninsula at about 0200 UTC Sunday.