The FBI arrested 150 people across the United States for holding children against their will for prostitution, a three-day weekend sweep that officials on Monday, July 29 called the largest-ever operation of its kind, Reuters reported.

The suspects were arrested in 76 U.S. cities and are expected to face state and federal charges related to sex crimes and human trafficking, FBI and U.S. Justice Department officials said at a news conference.

FBI agents and local police recovered 105 children during the operation at truck stops, motels, casinos and other places where they were held against their will for prostitution, officials said. Children who are most vulnerable to being exploited for sex crimes are between 13 and 16 years old without strong ties to family members, officials said.

"We are trying to take this crime out of the shadows and put a spotlight on it," said FBI Assistant Director Ronald Hosko.