LOS ANGELES (AP) — Immigration agents descended on dozens of 7-Eleven convenience stores before dawn Wednesday to begin checking on employees' immigration status in what officials described as the largest operation against an employer under Donald Trump's presidency.

Agents targeted about 100 stores nationwide, broadening an investigation that began four years ago with a case against a franchisee on New York's Long Island. The audits could lead to criminal charges or fines over the stores' hiring practices. Twenty-one people suspected of being in the U.S. illegally were arrested.

The action ap...