Weeping children pleaded with the Trump administration on Thursday to release their parents after hundreds of workers were detained in raids on food-processing plants in Mississipi.

“Dozens of children, some as young as toddlers, were bewildered when they were picked up from school and taken to makeshift shelters” after the raids on Wednesday, reports the New York Times. It was the first day of school in Mississippi.

Nearly 700 adults were taken into custody by immigration officers. Authorities said the raids were the largest ever conducted in a single state.

The children’s pleas for mercy raced around social media.

Government, please show some heart,” begged an 11-year-old girl whose father was among those detained.

“On Thursday afternoon,” says the Times, “state officials, immigration advocates, and lawyers still did not have a clear picture of what happened to those children, or who took custody of them.”

A  spokeswoman for the Mississippi Department of Child Protection Services (MDCPS) said the agency has “no idea what the number of children is, or where they are,” adding that the agency wasn’t notified of the federal raids ahead of time.

A spokesman for U.S. Immigration and Customs Enforcement (ICE) told the Associated Press via email that by Thursday afternoon nearly half of those arrested had been released.

“He did not say why they were let go except to say those released at the plants had been let go due to ‘humanitarian factors,’” the AP says.

A lawyer for the Mississippi Center for Justice told the Times “she had heard some had been given ankle monitors.” Others who remained in custody “were put on buses and driven across the state border to Louisiana,” where more detention beds were said to be available.