HONOLULU ? Environmental groups sued the federal government Wednesday to prevent the Navy from using active sonar during drills off Hawaii next month, saying the sound could harm whales and other marine mammals.

The Natural Resources Defense Council asked a federal court in Los Angeles to issue a temporary restraining order unless the Navy takes “effective measures” to protect marine life when it uses high-intensity, mid-frequency active sonar to hunt submarines in the drills.

The National Oceanic and Atmospheric Administration on Tuesday granted the Navy a permit to use sonar during war games involving more than 40 ships in Hawaii waters. The exercises are scheduled to start next week and last through late July.