The US Supreme Court has removed restrictions on the navy's use of sonar in training exercises near California. This is a huge blow for environmental groups who have been campaigning hard to protect whales and other marine life.

The Bush administration intervened in the long-running dispute, citing national security interests and argued that there is little evidence of harm to marine life in more than 40 years of exercises off the California coast.In its 5-4 ruling, the Supreme Court said the navy needed to conduct realistic training exercises to respond to potential threats.

The dispute involved 14 training exercises off the California coast that began in February 2007 and are scheduled to end in January 2009. In reinstating the use of sonar, the top US court rejected a lower federal judge's injunction that had required the US Navy to take various precautions during submarine-hunting exercises.It said that the judges should have deferred to the judgment of the navy and Mr Bush.

The court did not deal with the merits of the claims put forward by any of the environmental groups.