LOS ANGELES—Federal immigration authorities swarmed nearly 100 convenience stores in 18 states and the District of Columbia Wednesday morning and warned businesses that the Trump administration’s hard-line stance on immigration applies to them too.

“Today’s actions send a strong message to U.S. businesses that hire and employ an illegal workforce: ICE will enforce the law, and if you are found to be breaking the law, you will be held accountable,” said Tom Homan, deputy director of U.S. Immigration and Customs Enforcement.

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