A federal judge has ruled that some provisions of the US Patriot Act dealing with foreign terrorist organizations remain too vague to be understood by a person of average intelligence and are therefore unconstitutional.

US District Judge Audrey Collins found that Congress failed to remedy all the problems she defined in a 2004 ruling that struck down key provisions of America's main anti-terrorism tool. Her decision was handed down Thursday and released Friday.

"Even as amended, the statute fails to identify the prohibited conduct in a manner that persons of ordinary intelligence can reasonably understand," the ruling said.

'Too vague'

Collins issued an injunction against enforcement of the sections she found vague but specified that her ruling applies only to the named plaintiffs and does not constitute a nationwide injunction.

"I'm pleased that the court has recognized that people have a right to support lawful, nonviolent activities of groups the secretary of state has put on a blacklist," said David Cole, a Georgetown University law professor who argued the case on behalf of the Center for Constitutional Rights.

The center had sought to clear the way for US groups and individuals to assist political organizations in Turkey and Sri Lanka.

The case centered on two groups, the Liberation Tigers, which seeks a separate homeland for the Tamil people in Sri Lanka, and Partiya Karkeran Kurdistan, a political organization representing the interests of the Kurds in Turkey.

Both groups have been designated by the US as foreign terrorist organizations. However, the plaintiffs argued that there was a desperately increased need for aid following the tsunami disaster that devastated Sri Lanka last December.

Permissible aid

Without a clear definition of what aid is permissible, they said that those who provide assistance could be subject to 15-year prison terms.

The judge's ruling addressed the prohibition on providing material support or resources, including "training," "expert advice or assistance," "personnel" and "service" to designated foreign terrorist organizations.

The judge upheld the government position on a challenge to the ban on providing "personnel" to the named groups but found the other terms too vague.

'Service,' 'training'

"The court finds that the terms 'training,' 'expert advice or assistance' in the form of 'specialized knowledge' and 'service' are impermissibly vague," the judge concluded at the end of 42-page decision.

She enjoined the government from enforcing those provisions as they apply to the groups named in the lawsuit.