A huge Shell Oil drilling rig has run aground in a storm off the rugged coast of the remote U.S. state of Alaska.

The U.S. Coast Guard said the Kulluk broke free from the ship handling it in rough seas in the Gulf of Alaska on New Year's Eve and then was cut loose from a tug boat. In less than an hour, it ran aground on the rocky shoreline of the uninhabited Sitkalidak Island as winds reached more than 100 kilometers per hour.

Crew members were rescued before the grounding. Officials said the rig is carrying 567,000 liters of diesel fuel and 45,000 liters of lube oil and hydraulic fluid. There were no immediate signs the oil was leaking.

The grounding is the latest setback in Shell's efforts to explore for oil in Alaska's Arctic waters, which have been opposed by American Indian and environmental groups and hindered by damage to drilling equipment.