A coalition of environmental groups and Arctic communities has filed a second lawsuit aimed at blocking a Shell Oil subsidiary from drilling in the Beaufort Sea.

The group sued Tuesday, hours after a group that helps manage Eskimo whaling in Alaska filed a similar lawsuit.

Both suits aim to block plans by Shell Gulf of Mexico Inc. to drill two wells off Alaska's north coast.

Attorneys for Earthjustice filed the second lawsuit with the 9th U.S. Circuit Court of Appeals. They say the Minerals Management Service improperly approved Shell's drilling plan and did not properly evaluate effects of proposed drilling, including the risk of a major spill.

In response to the earlier lawsuit, a spokesman for Shell Alaska said MMS was thorough in its evaluation.