American officials staunchly defended a controversial raid arresting hundreds of immigrant workers at several Mississippi food processing plants as local authorities scrambled Thursday to address concerns about children left behind abandoned .

Immigration and Customs Enforcement agents arrested 680 mostly Latino men and women Wednesday who were working at seven plants in six cities in central Mississippi. About 300 were released Thursday with notices to appear before immigration judges.

Because the operation was secret, no arrangements were made for the migrants children, many of whom were left parentless with no one to pick them up at schools and day care, according to several local reports. Many children had nowhere to spend the night or anything to eat. It was the first day of school in the state.

This was a textbook operation, carried out in a safe manner , and done securely, acting ICE Director Matthew Albence insisted while traveling in Guatemala on Thursday, The Washington Post reported. Officers were able to execute these warrants in a safe fashion.

The operation, one of the largest single arrests of immigrants in more than a decade, was kept secret in part so President Donald Trump wouldnt boast about it on Twitter and tip off targets, the Post reported. About 600 federal agents were sent to the state to participate in the raids.

The operation occurred just hours before Trump traveled to Dayton, Ohio, and El Paso, Texas, in the wake of mass shootings in both cities. The attack on an El Paso Walmart has been linked to a vicious anti-immigrant manifesto authorities believe was written by the suspected gunman.

After the ICE raids, many children had to fend for themselves or depend on relatives, neighbors and strangers. A private gym owner in the town of Forest donated his space for children to sleep Wednesday night, and was arranging mattresses and donated food for them. I understand the law and how everything works ... but everybody needs to hold the kids first and foremost in their minds, gym owner Jordan Barnes told Channel 12 WJTV.

The National Education Association and the Mississippi Association of Educators issued a statement condemning the raids. We are outraged that ICE carried out these raids on the first day of school, causing chaos and separating families, the statement said. The trauma these students are enduring is inconceivable, and will have a profound long-term effect.

Nearly 24 hours after the raids began, it was still far from certain where all the children ended up, according to the Mississippi Department of Child Protection Services, the Post reported.

The Department of Child Protection Services was not notified beforehand of the ICE activity, nor have we been contacted by them after the fact, agency spokeswoman Lea Anne Brandon told the newspaper. It is frustrating because we have resources on the ground, trained, ready and licensed to respond to emergency situations , and we could have provided services that instead appeared to be put together in a makeshift fashion.

Some children were reunited with their parents Thursday morning when about half of those arrested were freed though other adults were sent to facilities in Louisiana, away from their families.

Some of [the children] knew nothing about where their parents were. When their parents were reunited with them, they ran up and started hugging and crying, and it touched my heart , Scott County Youth Court Prosecutor Constance Slaughter-Harvey told the Jackson Free Press on Thursday. But she said she struggled to place 30 children whose parents had been arrested in her county alone.

An ICE and Justice Department news release said that those arrested were given access to phones to arrange for someone to find and take care of their children. But there was no official in charge of tracking the children who had been left alone.

Hundreds of children were missing from school on Thursday, BuzzFeed reported. It wasnt clear if they couldnt obtain transportation to school, were too fearful to attend or were somehow otherwise at risk.

Former President Barack Obama s acting director of ICE, John Sandweg, slammed the Trump raids in an interview on National Public Radio on Thursday. He criticized the tremendous waste of resources that he said should be used instead on real safety threats.

The big problem with these worksite operations ... is the people you get are the responsible people who are trying to feed their family by showing up and giving an honest days work. Youre not going to find your criminals, Sandweg said.

It reinforces this perception that the administration is just targeting the parents of children, and then you hear children ... crying because their parents are not coming home that night.