The Associated Press

LOS ANGELES - The California Coastal Commission sued the U.S. Navy on Thursday over its decision to proceed with offshore sonar training exercises without precautions that state regulators say are necessary to protect whales and other marine life.

The lawsuit by the powerful agency is the first state action against the Navy over the issue of sonar training, which has been linked to the stranding deaths of whales and dolphins worldwide.

The commission earlier this year allowed the Navy to conduct the military exercises over a two-year period only if it took safeguards to protect marine mammals and sea turtles.

Among the restrictions imposed by the commission were avoiding coastal waters with large whale and dolphin populations and lowering sonar levels during periods of low visibility.

The Navy, in turn, sent a letter to the commission, saying it could not agree to the restrictions and will go ahead with the exercises, according to the lawsuit.

andquot;The actions of the Navy ... will lead to serious impacts on California's coastal resources,andquot; the suit said.

The commission contends a federal act gives it the power to regulate the Navy's sonar training to make sure it complies with a state law that protects coastal and marine resources. It is seeking a preliminary injunction against future sonar drills until the Navy agrees to the commission's limitations.

Commissioner Sara Wan said the Navy's unwillingness to comply with the restrictions left the state with no choice but to sue.

andquot;The Navy cannot simply arm-wave away the entire body of evidence ... that sonar can harm and kill marine mammals,andquot; Wan told reporters at a news conference.

Navy Vice Adm. Barry Costello, commander of the U.S. Third Fleet, would not comment on whether the commission has the power to regulate naval exercises.

andquot;We're disappointed with the decision to pursue litigation on this,andquot; Costello said. andquot;But we're doing our training that's essential to the Navy to support our armed forces, and we'll go forward and work with all the appropriate players on these lawsuits.andquot;

The use of sonar has been linked to harmful effects on whales and other marine mammals worldwide. A congressional report last year found the Navy's sonar exercises have been blamed on at least six cases of mass death and stranding among whales in the past decade.

The Navy periodically conducts sonar drills along the East Coast, the Gulf Coast, Hawaii and the Pacific Northwest to practice hunting submarines in nearshore waters. Sonar technology bounces pulses of sound off underwater objects to detect threats. However, environmentalists have blamed sound waves for hurting whales, possibly by damaging their hearing.

In a separate lawsuit filed Thursday in federal court, a coalition of environmental groups led by the Natural Resources Defense Council faulted the Navy for failing to prepare an environmental impact report on the planned drills. It is the fifth time the NRDC has sued the Navy over the sonar issue.

On Wednesday, the Navy refused to turn over sonar data to a federal court in a case involving potential harm to whales, saying the information could jeopardize national security.

The Navy had previously said many factors can cause marine animals to be beached, including pollution and starvation.