U.S. Immigration and Customs Enforcement agents take part in Operation Cross Check in September 2011.

Story highlights

NEW: There are still 1 million convicted criminal immigrants in U.S., ICE says

The latest operation spanned all 50 states and four U.S. territories

Nearly 1,300 had multiple convictions, ICE officials say

"Cross Check" operations have taken in more than 7,400 criminal aliens

Washington CNN  — 

In a huge, seven-day operation covering all 50 states and four U.S. territories, U.S. Immigration and Customs Enforcement officials arrested 2,901 convicted criminal immigrants as part of the “Cross Check” enforcement operation, ICE officials announced Wednesday.

ICE officials trumpeted the arrests at a news conference designed to highlight “the Obama administration’s ongoing commitment to prioritizing the removal of criminal aliens and egregious immigration law violators.”

ICE Director John Morton said all those arrested had prior criminal convictions, including 1,282 who had multiple convictions. More than 1,600 of those arrested had felony convictions including manslaughter, attempted murder, kidnapping, armed robbery, drug trafficking, child abuse, sexual crimes against minors and aggravated assault. Forty-two of them were gang members and 151 were convicted sex offenders, officials said.

ICE officials acknowledged that despite the large number of arrests, there were still an estimated 1 million convicted criminal aliens in the United States. Morton said one of the issues ICE is trying to deal with is the lack of notification to immigration authorities when offenders are released from jail.

Most of the people detained – 2,642 – were men. Those arrested came from 115 countries, with immigration fugitives accounting for 681 of those detained in the operation, Morton said. Of the people arrested, 386 were illegal re-entrants.

“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,” Morton in a statement released before the news conference. “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.”

ICE began conducting large-scale operations to target convicted criminal aliens in December 2009 and since then, nine regional and national Cross Check operations – including last week’s – have resulted in the arrest of more than 7,400 convicted criminal aliens.

CNN’s Athena Jones and Terry Frieden contributed to this report