MORTON, Miss. -- It was the first day of school in Morton, Mississippi, Wednesday, and many undocumented parents and their children went together to the first morning drop off, said Elizabeth Iraheta. By the end of the day, some of those children were all alone, she said.
US immigration authorities arrested about 680 undocumented immigrants at seven sites in six different cities in Mississippi on Wednesday. The raids are "believed to be the largest single-state immigration enforcement operation in our nation's history," said US Attorney for the Southern District of Mississippi Mike Hurst.
Officials declined to provide details about what sites had been targeted, citing what they said was an ongoing criminal investigation. CNN affiliates reported the raids occurred at food processing plants throughout the state.
Iraheta shared a Facebook video she recorded outside a plant in Morton that showed an 11-year-old girl sobbing and begging an officer for a chance to see her mother as bystanders tried to comfort her.
It was devastating, Iraheta said, to see family and friends suffering "just for coming to work hard in this country, and to see so many families separated."
In Forest, strangers and neighbors volunteered to take children with nowhere to go after their guardians were taken in the raid to a local gym for the night, according to CNN affiliate WJTV. Volunteers distributed donated food and drinks but most children sobbed rather than ate, the station reported.
William Truly Jr., the mayor of Canton, one of the cities where raids took place, told reporters Wednesday that the arrests are an order of the US, and so he doesn't think there is anything that can be done to stop it.
"But my main concern is now, what happens to the children?" he told reporters outside a processing plant owned by Peco Foods Inc.
Laws and their enforcement 'not new'
Immigration and Customs Enforcement has stepped up worksite enforcement since President Donald Trump took office, conducting a number of large-scale raids at food-processing plants and gardening centers in recent years.
"These are not new laws, nor is the enforcement of them new," acting ICE director Matt Albence said Wednesday.
"The arrests today were the result of a year-long criminal investigation. And the arrests and warrants that were executed today are just another step in that investigation."
Albence told reporters Wednesday that some parents will be released and placed on ankle monitoring throughout their immigration proceedings and that in the past the agency has worked with school liaisons to help "find placement" for children when their parents are detained.
Some people have already been released
By Wednesday night, US Immigration and Customs Enforcement spokesman Bryan Cox told CNN that some of the people detained had been released.
Officials have not specified why some were released.
"Any suggestion that all persons are going to be detained is not correct," Cox said.
Other detainees are still being processed, he said.
Confidential informants helped in raids
A senior immigration official with knowledge of the investigation told CNN that ICE used confidential informants employed at several of the raided food processing plants to identify managers or supervisors who knew they were hiring undocumented workers. In some cases, immigration enforcement received audio and video recordings.
CNN has reached out to the food processing plants for comment.
