U.S. immigration authorities announced Wednesday the arrests of 2,901 undocumented immigrants with criminal records over the last week as part of a national "Cross Check" enforcement operation.

At a press conference, the director of Immigration and Customs Enforcement, John Morton, said all the arrested people have at least one criminal conviction apart from any violations of immigration legislation.

"The results of this targeted enforcement operation underscore ICE's ongoing commitment and focus on the arrest and removal of convicted criminal aliens and those that game our nation's immigration system," he said.

"Because of the tireless efforts and teamwork of ICE officers and agents in tracking down at large criminal aliens and fugitives, there are 2,901 fewer criminal aliens in our neighborhoods across the country," Morton said.

The operation was mounted by more than 1,900 ICE agents as well as local and state authorities. Many of the 2,642 men and 259 women detained are Latin Americans.

ICE undertook the first Cross Check raid California in December 2009. Since then, the agency, in cooperation with local authorities, has arrested more than 7,400 foreigners with criminal records.

The most recent phase of the operation took place last week in all 50 states, Puerto Rico and other U.S. territories.

About half of the arrested people were convicted of serious crimes such as manslaughter, attempted murder, kidnapping, armed robbery, drug trafficking, child abuse, sexual crimes against minors and aggravated assault.

The group of arrested people includes citizens of 115 nations.

Also arrested were 42 gang members.

A month ago, Homeland Security Secretary Janet Napolitano said that the situation of some 300,000 undocumented immigrants whose deportation procedures are under way would be examined on a "case by case" basis and that the government would give priority to expelling criminals and those who pose a threat to national security.

Morton said Wednesday that the review still had not been started.

Republican lawmakers and immigration opponents have criticized Napolitano's decision, claiming that it constitutes "backdoor amnesty" for undocumented immigrants who do not have criminal records.

In remarks to Efe, ICE agent Lloyda Rocha said that the majority of the people arrested last week were deported or are in the process of being deported.