Los Angeles: A coalition of legal groups and Tamil sympathisers in the United States is mounting a challenge to a law, which makes it an offence to provide advice and assistance to groups deemed by the government as "terrorists".

The challenge, filed in federal court of Los Angeles, is the latest attack on the Patriot Act, enacted following the September 11, 2001 attacks, which some rights group say erodes civil liberties.

Secretary of State Colin Powell and Attorney General John Ashcroft are named as defendants in the lawsuit, filed as an extra submission to an existing case on August 5, and lodged as a separate complaint on August 27.

Six groups and two individuals party to the suit say they want to support the "lawful and humanitarian activities" of the Liberation Tigers of Tamil Eelam (LTTE) of Sri Lanka and the Kurdistan Workers Party (PKK) from Turkey.

Both organisations, fighting for a separate state, have been designated "terrorist" organisations by the State Department.

The lead plaintiff in the case is the Los Angeles- based Humanitarian Law project, which is joined by other groups including the world Tamil Coordinating Committee in New York and other Tamil American groups.

Lawyers from the Centre for Constitutional Rights, which is arguing the case, are challenging a Patriot Act amendment to the Anti-terrorism and Effective Death Penalty Act of 1996.

Agencies