A day after what officials called the biggest work site immigration enforcement operation in a single state, Mississippi residents were still shaken by the arrests of nearly 700 workers, most of them Latino, and bracing for the ongoing impact of the raids.

"What I saw was traumatic, painful," Elizabeth Iraheta, who witnessed the raid on a food processing plant where she works in Morton, said Thursday in Spanish in a phone interview. "I'm thinking of the separated families, fathers and mothers deported, children left alone because their parents were arrested."

Immigration and Customs Enforcement, or ICE, conducted raids in six cities at seven sites around Mississippi on Wednesday, detaining 680 people suspected of being undocumented immigrants. Officials said the enforcement actions were the culmination of a yearlong investigation.

ICE officials said on a news teleconference Thursday afternoon that about 300 of those who were detained had been released from custody and placed into proceedings before federal immigration courts, with 32 others released at the work sites and 271 more released from a processing center. Those who remained detained were being held in Louisiana and Mississippi, the officials said.

Iraheta, 49, took a video of the enforcement operation at the Koch Foods processing plant on Wednesday after seeing immigration agents and a helicopter. A 12-year-old girl, Angie, whose mother was detained in the raid, was with Iraheta.

"This is something that's going to stay in her mind her whole life," Iraheta said.

She said she stayed up with the girl into the early morning hours of Thursday, waiting for her mother to come home. The family rents a room from Iraheta. Finally, on Thursday morning, the girl's mother came home after being released from custody, Iraheta said.

"We have barely slept waiting for her return," she said. "They were very long hours for the little girl. She was anguished, asking me what was happening."

Mike Hurst, the U.S. attorney for Southern Mississippi, said at a news conference after the raids that the country must uphold the law above all else.

"While we are a nation of immigrants, more than that, first and foremost, we are a nation of laws," Hurst said. "They have to come here legally, or they shouldn't come here at all."

In the video taken by Iraheta, the girl is teary-eyed as an unidentified immigration officer explains what will happen next and comforts the girl.

"She just went. Her mom just got on the bus. We took her mom's documents, OK," the agent says. "She's going to be processed, because she doesn't have papers to be here legally."

The agent adds that because Angie is a U.S. citizen and her mother is her sole caretaker, the mother would likely be released the same day and given a notice to appear before an immigration judge.

"But I'm going to tell you something, she's not going to be deported, because she has a United States citizen child," the agent says.

Iraheta told NBC News that she took the video "so the community could know what was happening."

An NBC News reporter captured pictures and stories of other families who had also been affected:

This is Deily. She’s barely 1. She’s sleeping in a makeshift bed at a church in #Mississippi. Her mother was 1 of nearly 700 immigrants taken yesterday during the #ICEraidsMS and her father had 2 leave her with their pastor while he picks up his other 2 kids. @NBCNews @NBCLatino pic.twitter.com/1OandjmTmv — Annie Rose Ramos (@Annie_Rose23) August 8, 2019

This is Margarita and her 9yo daughter. She’s crying b/c her Dad was taken yesterday during the #ICERaids #ICEraidsMS . She says she didn’t go to school today b/c she is so upset. Her Mom says she didn’t go to bed until 3am last night. @NBCNews @MSNBC pic.twitter.com/Ss6wXW0Wao — Annie Rose Ramos (@Annie_Rose23) August 8, 2019

Meanwhile, immigration advocates and aid organizations were coming together Thursday to ask volunteers to help affected families with legal assistance and donations. They described children on their first day of school who were suddenly left without parents, turning to strangers or distant relatives for help as they waited for answers.

Cliff Johnson, director of the MacArthur Justice Center at the University of Mississippi School of Law, told NBC News that he and others had set up a hotline for families who were affected by the raids to call and for volunteers looking to help.

He said a raid of such size would lead to major economic consequences in the affected communities in the coming weeks.

"We're going to see dramatic financial consequences. This affects housing, access to food," he said. "I have real concerns about what happens a week and two weeks from now from a financial perspective for these families."

"Logistically, this is not something for which we were prepared," he said.