The Justice Department filed another lawsuit against immigration practices by Arizona authorities, saying Monday that a network of community colleges acted illegally in requiring noncitizens to provide their green cards before they could be hired for jobs.

The suit against the Phoenix-area Maricopa Community Colleges was filed less than two months after the Justice Department sued Arizona and Gov. Jan Brewer (R) over the state's new immigration law. It also comes as the department is investigating Joe Arpaio, the sheriff in Maricopa County, who is known for tough immigration enforcement.

In Monday's lawsuit, Justice officials said the colleges discriminated against nearly 250 noncitizen job applicants by mandating that they fill out more documents than required by law to prove their eligibility to work. That violated the federal Immigration and Nationality Act, the department said.

The law's antidiscrimination provision "makes it unlawful to treat authorized workers differently during the hiring process based on their citizenship status," said Thomas E. Perez, assistant attorney general for Justice's Civil Rights Division. He said the government "is acting now to remedy this pattern or practice of discrimination."

Tom Gariepy, a spokesman for Maricopa Community Colleges - which operates 10 colleges and two vocational training centers in and around Phoenix - declined to comment.

Justice Department officials said the lawsuit is unrelated to the case against Brewer and the probe of Arpaio and stems from a different investigation that began in January 2009 - the month the Obama administration took office.

It is the latest example of stepped-up enforcement by the department's Civil Rights Division, which has been reshaping itself after an exodus of lawyers during the Bush administration. It filed a similiar lawsuit in April against John Jay College of Criminal Justice in New York.

The lawsuit was filed Tuesday before the Executive Office for Immigration Review, a Justice Department unit that adjudicates immigration cases. It was filed on behalf of Zainul Singaporewalla, a U.S. permanent resident who applied for a math teaching position at Glendale Community College, part of the Maricopa network.

After filling out a federal form attesting to his immigration status and producing a driver's license and Social Security card, he was told to complete another form with more immigration-related information, the lawsuit said.

That form required other documents and his green card. When he couldn't present his green card, the lawsuit said, the college would not process his paperwork and declined to hire him.

The government is asking a judge within the Justice Department unit to order the Maricopa colleges to pay a civil penalty of $1,100 for each of the 247 non-U.S. citizen job applicants it says were required to produce the additional documents. It says the colleges ended the practice in January.