Shell began work on its controversial Arctic project Sunday . An ice floe forced the company to halt work on Monday . The U.S. Coast Guard said it was investigating a report of an oil spill in Alaska's Cook Inlet, but no injuries were reported and there is "no indication that any hazardous materials have been released. " CNN 's Miguel Marquez contributed to this report . Environmental groups say a spill there would be catastrophic .
Shell began work on its controversial Arctic project Sunday . An ice floe forced the company to halt work on Monday . The U.S. Coast Guard said it was investigating a report of an oil spill in Alaska's Cook Inlet, but no injuries were reported and there is "no indication that any hazardous materials have been released." Environmental groups say a spill there would be catastrophic .