JACKSON, Miss. — Dozens of immigrant workers have been released a day after being detained in the largest immigration raid in a decade in the United States.

Immigrations and Customs Enforcement officials say 680 people were arrested in Wednesday’s raids.

But immigration lawyers say that by Thursday morning, about five busloads of people had been released.

The terms of the workers’ releases were unclear. It also was unclear whether any of those released were determined to be living in the country legally. ICE officials did not return telephone calls Thursday morning.

Officials had said Wednesday that they would release detainees who met certain conditions, such as pregnant women or those who hadn’t faced immigration proceedings previously.

Karla Vazquez-Elmore is a lawyer representing arrested workers. She said even those not arrested are terrified.