A federal judge has ruled that immigration officials acted improperly in denying political asylum to six Salvadorans, casting doubt on the method used to curb the influx of Central American refugees.

Regulations require the Immigration and Naturalization Service to adjudicate requests for work authorization from any alien who has filed an application for asylum that is "non-frivolous."But in a ruling that suggests that the INS has been dismissing asylum applications as frivolous without fully considering their merits, U.S. District Judge William Wayne Justice ordered the agency to readjudicate work authorization requests for six Salvadorans.

The ruling, signed Friday but only released to lawyers in the case Monday, also ordered the INS to consider a work authorization request from a seventh Salvadoran.

The ruling is particularly significant in south Texas, where the INS detains refugees and considers most applications frivolous, according to Robert Rubin, a San Francisco lawyer who represents the Salvadorans.

"The INS sees the denial of work authorizations as a means to discourage persons from pursuing their asylum claims," Rubin claimed Tuesday.

The New York Times on Wednesday quoted Rubin as saying he had already filed a petition to make the judge's ruling apply to all asylum applicants in Texas.

The newspaper also said government lawyers arguing the case had told the judge the country would face a "flood of illegal aliens" if the policy for considering work authorization requests was struck down.