Federal immigration agents were deployed to the Atlanta airport during the partial closure

ATLANTA (AP) — Federal immigration officers were seen at an airport in Atlanta after President Donald Trump said he would deploy agents to supplement the Transportation Security Administration during a government shutdown that has caused long lines at security checkpoints across the country.

On Monday morning, The Associated Press saw a group of federal agents near busy lines at Hartsfield-Jackson Atlanta International Airport.

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Federal agents are routinely present at international airports, where Customs and Border Protection agents screen incoming travelers and Homeland Security Investigations agents handle criminal cases related to smuggling, trafficking and fraud.

What’s unusual at the moment is their appearance at TSA security checkpoints, a role typically held by transportation security officers rather than federal investigators.

Hundreds of thousands of DHS workers, including from the Transportation Security Administration, the U.S. Secret Service and the Coast Guard, have worked without pay since Congress failed to renew DHS funding last month.

Some fear the move to deploy federal immigration agents will escalate tensions.

Read more: Federal immigration agents have been sent to US airports to bolster security during the budget crisis

Trump said Sunday he would order federal immigration agents to airports to assist the TSA by guarding exit lanes or checking passengers’ identities unless Democrats agree to fund the Department of Homeland Security. Funding for the department expired on February 14, as Democrats refused to fund ICE as well as Customs and Border Protection without making changes to their operations in the wake of the deaths of Alex Peretti and Renee Judd in Minneapolis.

Democrats continue to demand major changes to federal immigration processes — including policy changes that would require ICE agents to obtain a warrant from a judge before forcibly entering homes, and to remove masks and clear identification information on uniforms.

Read more: Trump says he will order federal immigration officers to help with airport security unless Democrats end the shutdown

Trump on Monday directed Immigration and Customs Enforcement officers not to wear face coverings while working at airports. In a social media post, Trump said he supports ICE officers wearing masks when dealing with “hardened criminals” but noted that it is not necessary when helping with “chaos at airports.”

Grantham Phillips reported from New York. Associated Press writer Colleen Binkley in Washington contributed to this report.