In a series of tweets Monday night, President Donald Trump threatened mass deportations of undocumented immigrants, and said they could happen as soon as next week.

The posts from Trump signaled that a shelved plan for raids in major cities, an idea challenged by former administration officials, could be back on.

“Next week ICE will begin the process of removing the millions of illegal aliens who have illicitly found their way into the United States,” Trump tweeted. “They will be removed as fast as they come in.”

The Washington Post reported that Trump and his senior immigration adviser, Stephen Miller, “have been prodding Homeland Security officials to arrest and remove thousands of family members” whose cases have been expedited as a part of a plan called the “rocket docket.”

It was revealed in May that Trump had purged the Department of Homeland Security after then-Homeland Security Secretary Kirstjen Nielsen and then-acting ICE Director Ronald Vitiello were critical of a plan to carry out mass arrests of thousands of migrants in 10 major American cities. The plan, the Post reported at the time, was to target families. Nielsen and Vitiello’s objections at the time were over “logistical and operational” concerns, rather than ethical qualms.

It’s not entirely clear if the administration is preparing to carry out the deportations Trump promised, but acting ICE Director Mark Morgan said this month he planned to ramp up arrests of people who’ve received their final deportation orders, including families.

The Associated Press reported Monday night, citing an anonymous administration official, that the arrests would target the “more than 1 million people who have been issued final deportation orders by federal judges but remain at large in the country.” It would seem, then, that Trump was tweeting about a plan that is actually in place and not on a whim, as he is wont to do.

Morgan claimed the deportations would be carried out with “with compassion and humanity.” But promises to carry out deportations in a compassionate way have never come to fruition, despite similar claims from numerous administrations: There’s no kind way to uproot someone's life against their will, and no nice method for sending a person back to a dangerous situation.

In what's sure to be a frightening time for undocumented immigrants, RAICES, a Texas nonprofit that provides legal services to immigrants, was quick to remind people of their rights. If ICE raids your workplace, the group noted in tweet responding to Trump, you don’t have to speak, you do have the right to a lawyer, and you don’t have to sign any documents.