U.S Immigrations and Customs Enforcement officially launched "enhanced targeted operations" in Chicago on Sunday, following a week-long frenzy of reported sightings since President Trump’s inauguration.

A top Department of Justice official and President Trump’s “border czar” were in Chicago overseeing “immigration enforcement efforts,” according to officials. “The DEA, along with our

ICE reported 956 arrests on Sunday, 286 on Saturday, and 593 on Friday. Border czar Tom Homan says this is only the beginning.

Nearly 500 shipments containing just over 15,000 weapon-modifying devices or Glock switches were recovered by Customs and Border Protection agents in Chicago. The CBP says the majority of the shipments came from China.

More than 1,500 weapon-modifying devices were seized by U.S. Customs and Border Protection (CBP) officers stationed in Chicago last year. According to the CBP, offices stationed in

In a statement posted to social media, U.S. Immigration and Customs Enforcement (ICE) announced the effort alongside “federal partners.”

CBP One, a border app that has allowed nearly 1 million people to legally enter the United States with eligibility to work, was abruptly shut down on Monday, shortly after President-elect Donald Trump took office.

Most of the Glock switch shipments had come from China, and were destined for various locations throughout the United States, CPB said.

Customs agents in Chicago said they seized thousands of illegal Glock switches shipped into the city last year, according to a statement Tuesday from the U.S. Customs and Border Protection.

With two top Trump administration officials in Chicago, federal law enforcement began a “targeted” immigration blitz Sunday, according to a spokesman for U.S. Immigration and Customs Enforcement. The agency did not say how many arrests have taken place so far.

The Trump administration Monday ended use of a border app called CBP One that has allowed nearly 1 million people to legally enter the United States with eligibility to work.

The CBP One app has been highly popular, functioning as an online lottery system that grants appointments to 1,450 people daily at eight border crossings. These individuals enter the U.S. under immigration "parole," a presidential authority that Joe Biden has exercised more frequently than any other president since its creation in 1952.