In the largest such operation ever, the U.S. Immigration and Customs Enforcement arrested 286 foreign nationals in California with criminal records in a three-day enforcement surge that ended Thursday night.

Of those taken into custody, 119 were from Northern California and 24 were from the San Jose area.

ICE reported about 80 percent of the immigrants taken into custody had prior convictions for serious or violent crimes such as rape, armed robbery and assault with a deadly weapon. Also arrested were 30 convicted sex offenders, many of whom had been convicted of sexual assaults on children.

At a news conference in Los Angeles this morning, John Morton, the Homeland Security assistant secretary who oversees ICE, announced the results of the special operation, which involved more than 400 agents and officers from ICE, the U.S. Marshals Service, as well as several other state and local agencies.

“Enhancing public safety is at the core of ICE’s mission,” Morton said. “Legal immigration is an important part of our country’s history, and the American dream exists for many immigrants. However, that dream involves playing by the rules, and those who break our criminal laws will be removed from the country. “Sadly,” he added, “many of the people victimized by aliens who commit crimes are other members of the immigrant community who are following the rules.”

Of those arrested in the enforcement surge, more than 100 have already been removed from the country, said Virginia Kice, an ICE spokeswoman. She said at least 17 of the people taken into custody will face further federal prosecution, most for re-entering the country illegally after a formal deportation. A felony conviction on that charge carries a penalty of up to 20 years in prison.

Kice said the special enforcement action was spearheaded by ICE’s Fugitive Operations Program, which locates, arrests and removes immigrants with criminal records as well as “immigration fugitives” — people who have ignored final orders of deportation handed down by immigration courts.

She said ICE gives top priority to cases involving legal and illegal immigrants who pose a threat to national security and public safety, including members of transnational street gangs and child sex offenders.

In the fiscal year that ended Sept. 30, ICE’s fugitive operation teams made 35,094 arrests nationwide. More than 3,600 of those arrested had been convicted of violent crimes such as murder and assault.