The United States says it has arrested 2,900 illegal immigrants — all with prior criminal convictions — during a seven-day sweep across the country.

U.S. Immigration and Customs Enforcement said Wednesday the operation was the largest of its kind, leading to arrests in all 50 U.S. states and in four U.S. territories.

The arrests come a month after Homeland Security Secretary Janet Napolitano said a new focus would be put on deporting criminals and serious violators of immigration law.

More than 1,200 of the illegal immigrants arrested in last week's operation had multiple convictions, while more than 1,600 had convictions including manslaughter, attempted murder, kidnapping, sexual crimes against minors, drug trafficking and armed robbery.

The ICE-led operation, dubbed “Cross Check,” follows several similar operations that have resulted in the arrest of more 4,500 convicted illegal immigrants since 2009.

With an estimated 11 million undocumented immigrants living in the U.S., ICE Director John Morton said the operation underscores the Obama's administration's commitment to the arrest and removal of illegal immigrants with criminal convictions.

Also Wednesday, a federal judge is set to rule on a lawsuit challenging a controversial immigration law in Alabama.

The law would allow Alabama police to detain anyone suspected of being in the country illegally when that person is stopped for any other reason. It would also make it a crime to knowingly transport or harbor an illegal immigrant, and compel public schools to verify the immigration status of students.

A coalition of civil rights groups filed a class action lawsuit against the measure, saying it invites racial profiling and will target for harassment anyone who looks “foreign.”

The U.S. Department of Justice has also challenged the act, saying it would conflict with federal immigration policies.