The Trump administration has abruptly shifted the focus of its mass deportation campaign, telling Immigration and Customs Enforcement officials to largely pause raids and arrests in the agricultural industry, hotels and restaurants, according to an internal email and three U.S. officials with knowledge of the guidance.

The decision suggested that the scale of President Trump’s mass deportation campaign — an issue that is at the heart of his presidency — is hurting industries and constituencies that he does not want to lose.

The new guidance comes after protests in Los Angeles against the Trump administration’s immigration raids, including at farms and businesses. It also came as Mr. Trump made a rare concession this week that his crackdown was hurting American farmers and hospitality businesses.

The guidance was sent on Thursday in an email by a senior ICE official, Tatum King, to regional leaders of the ICE department that generally carries out criminal investigations, including work site operations, known as Homeland Security Investigations.

“Effective today, please hold on all work site enforcement investigations/operations on agriculture (including aquaculture and meat packing plants), restaurants and operating hotels,” he wrote in the message.

The email explained that investigations involving “human trafficking, money laundering, drug smuggling into these industries are OK.” But it said — crucially — that agents were not to make arrests of “non-criminal collaterals,” a reference to people who are undocumented but who are not known to have committed any other crime.