WASHINGTON, United States (CMC) — US Federal immigration agents on Wednesday arrested several undocumented workers when they descended on dozens of convenience stores across the country, targeting illegal Caribbean and other immigrants.

The agents descended on 7-Eleven convenience stores before daybreak, arresting undocumented workers and demanding paperwork from managers, in what the Trump administration described as its largest enforcement operation against employers so far.

The sweeps of 98 stores in 17 states, from California to Florida, resulted in 21 arrests, according to United States Immigration and Customs Enforcement (ICE), which signalled intensified efforts against businesses that hire unauthorised workers.

“Today’s actions send a strong message to US businesses that hire and employ an illegal work force: ICE will enforce the law, and if you are found to be breaking the law, you will be held accountable,” said Thomas D Homan, the acting director of the agency, in a statement.

Homan, the US’s top immigration-enforcement official, has promised more scrutiny of businesses that knowingly violate federal laws requiring employers to verify the identity and employment eligibility of their workers.

Under President Trump, ICE has significantly expanded immigration enforcement, arresting undocumented Caribbean and other immigrants in their homes or when they check in with US federal agents as part of immigration court cases.

In a statement, 7-Eleven Inc, based in Irving, Texas, distanced itself from the situation, saying that the individual stores are franchises that belong to independent business owners, who “are solely responsible for their employees, including deciding who to hire and verifying their eligibility to work in the United States.”

“7-Eleven takes compliance with immigration laws seriously and has terminated the franchise agreements of franchisees convicted of violating these laws,” the company said.

If ICE hoped to make a bold statement, it could hardly pick a more iconic target than 7-Eleven, a chain known for ubiquitous stores that are open all the time and sell the much-loved Slurpees and Big Gulps, the New York Times said in a report adding that several  7-Eleven franchises have been steppingstones for new legal immigrants who want to own and run their own small businesses.

ICE called its Wednesday sweep a “follow-up” of a 2013 investigation that resulted in the arrests of nine 7-Eleven franchise owners and managers on Long Island, New York and in Virginia on charges of employing undocumented workers.

Several have pleaded guilty and forfeited their franchises, and have been ordered to pay millions of dollars in back wages owed to the workers.

According to ICE, federal agents served inspection notices to 7-Eleven franchises in California, Colorado, Delaware, Florida, Illinois, Indiana, Maryland, Michigan, Missouri, Nevada, New Jersey, New York, North Carolina, Oregon, Pennsylvania, Texas, Washington State and Washington, D.C.

In all, 16 of the 98 stores visited on Wednesday were in the New York City area, according to an ICE spokeswoman, Rachael Yong Yow, who would not specify the locations.

In Miami Beach, an employee at one 7-Eleven said that while no agents showed up at her store, her boss asked workers to make sure their employment records were up to date, in case ICE continued its visits, according to the Times.

It said agents dropped in on 7-Eleven stores in seven cities in southeast Florida, including Miami Beach, according to Nestor Yglesias, an ICE spokesman; he, too, declined to identify specific stores.

Wednesday’s raids were made amidst intense political battle about a US federal programme that shields from deportation young Caribbean and other immigrants who were brought illegally to the US as children.

Stating that the decision to kill the programme was improper, Judge William Alsup of Federal District Court in San Francisco wrote on Tuesday that the Trump administration must “maintain the DACA programme on a nationwide basis,” as the legal challenge to the US president’s decision proceed.

President Barack Obama created the Deferred Action for Childhood Arrivals programme (DACA)  in 2012 to also give young immigrants the ability to work legally in the United States.

President Donald Trump moved to end the programme in September, saying that Obama’s actions were unconstitutional and an overreach of executive power.

This has reportedly set off a fierce debate in Washington as Democrats and Republicans spar about how to provide relief for about 800,000 immigrants who could face deportation when the programme ends on March  5.