Federal law enforcement at Immigration and Customs Enforcement has made worksites a major focus of its strategy, going after illegal immigrants at job sites in the hopes of rounding up large numbers of people at one time, according to two sources with firsthand knowledge.

“Worksite enforcement is the big ticket now,” said the first official, who was not authorized to speak with the media and spoke on the condition of anonymity. “They’re going to be doing a lot of those types of operations.”