WASHINGTON, Dec. 13 (Xinhuanet) -- The US Federal Bureau of Investigation (FBI) has implemented new ground rules that fundamentally alter the way investigators handle counterterrorism cases, The Washington Post reported Saturday.

    The new rules allow criminal and intelligence agents to work side by side and giving both broad access to the tools of intelligence gathering for the first time in decades.

    The result is that the FBI, unhindered by the restrictions of the past, will conduct many more searches and wiretaps that are subject to oversight by a secret intelligence court rather than regular criminal courts, officials were quoted as saying.

    The new strategy, which was launched in early summer and finalized in a classified directive issued to FBI field offices inOctober, marks the final step in tearing down the legal wall that had separated criminal and intelligence investigations since the spying scandals of the 1970s, the report quoted authorities as saying.

    Senior FBI officials said the changes have helped the bureau disrupt plans for at least four terrorist attacks overseas and uncover a terrorist sleeper cell in the United States, and resulted in a notable surge in the number of counterterrorism investigations.

    Attorney General John Ashcroft, FBI Director Robert Mueller andother officials argue such changes are necessary to transform the FBI from a reactive law enforcement agency into one capable of detecting and thwarting terrorist attacks before they occur.

    But several civil liberties advocates and defense lawyers said the new FBI rules appear to encourage agents to ignore constitutional concerns and to push the boundaries of what is allowed by recent court rulings, and that the changes would pose athreat to the privacy of civilians.

    "By eliminating any distinction between criminal and intelligence classifications, it reduces the respect for the ordinary constitutional protections that people have," said JoshuaL. Dratel, a New York lawyer who has filed legal briefs opposing government anti-terrorism policies. Enditem