(Reuters) - U.S. authorities launched small-scale operations seeking to arrest undocumented immigrants over the weekend in an apparent start to President Donald Trump’s vow to launch mass deportation round-ups across the United States.

The operation, which Trump revealed on Twitter last month, then postponed before telling reporters on Friday that it would proceed, was expected to target hundreds of recently arrived families in about 10 cities who had been ordered deported by an immigration judge.

The removal operations are meant to deter a surge in Central American families fleeing poverty and gang violence in their home countries, with many seeking asylum in the United States.

Immigrants and their advocates were bracing for mass arrests, but by Sunday night there were only reports of low-profile operations in a few cities.

“We are doing targeted enforcement actions against specific individuals who have had their day in immigration court and have been ordered removed by an immigration judge,” Acting Immigration and Customs Enforcement (ICE) Director Matt Albence told Fox News when asked for an update.

Mary Bauer at the Southern Poverty Law Center (SPLC) said there were no confirmed operations in large Southern cities such as Atlanta.

There also were no reports of arrests from the American Immigration Council, which has lawyers on standby to give legal advice at the country’s largest family migrant detention center in Dilley, Texas.

“Immigrants and immigrant communities all over the country are in hiding and people are living in these terrified, terrorized ways, because that is the point of this whole action, whether enforcement actions take place or not,” said Bauer, the SPLC’s deputy legal director.

“LIGHTS OFF, BLINDS DOWN”

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New York Mayor Bill de Blasio said there were three ICE operations in his city on Saturday, with no reported arrests. He said there was no ICE activity in New York on Sunday.

“This is a political act by this president, he’s politicized a United States government agency to help him win re-election,” said de Blasio, a Democratic candidate for the 2020 presidential race.

In Denver, the Colorado Rapid Response Network of immigration activists said there were unconfirmed reports of ICE or police detaining three people on Sunday in the Potter Highlands area.

The Miami-based Florida Immigrant Coalition said immigrants were sheltering at home after ICE agents were seen near the city’s international airport. No arrests were reported.

“They’ve been stocking up on groceries and making plans to stay in their homes with the lights off and the blinds down,” the group posted on Facebook. “Some are staying home from work.”

An ICE spokeswoman declined to comment on operations, citing the safety of the agency’s personnel.

Albence told Fox News that enforcement operations would target families who entered the country illegally then mostly failed to attend court hearings to pursue an asylum claim.

Immigration rights activists have said that in many cases immigrants do not receive proper notice of their court dates.

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The operations came as the Trump administration faces criticism for housing immigrants in overcrowded, unsanitary conditions, and there are concerns about migrant children being separated from adults by U.S. authorities.

“While we haven’t heard of widespread sweeps, none of our communities should have to live in fear that parents won’t come home from work, or kids won’t return from school,” said Lauren Weiner, communications director for the American Civil Liberties Union, which sued this week to stop the arrests going ahead.

In a typical week, ICE arrests thousands of immigrants who are staying in the country illegally, according to government data. Most of those arrests are made without advance publicity.

Amid protests outside ICE facilities, a 69-year-old gunman was shot dead by police early on Saturday after he attacked an immigration detention center in Tacoma, Washington and set fire to at least one vehicle outside.

The suspect, who was armed with a rifle and incendiary devices, was identified on Sunday as Willem Van Spronsen, who was arrested last year for assaulting a police officer during a protest outside the same facility.