RIVERSIDE -

A search of a Riverside home revealed 37 illegal immigrants, including a half-dozen children, smuggled into the country and being held against their will, authorities reported today.

Agents with U.S. Immigration & Customs Enforcement discovered the illegal aliens while executing a search warrant Tuesday at 1879 Martin Luther King Blvd.

According to ICE, federal investigators suspected the location was a smuggling "drop house" and that at least one person was imprisoned there.

That information had been provided by a Los Angeles resident, who reported that a relative was smuggled into the country and was being kept in the Riverside area until the smugglers were paid off, authorities said.

The relative's life had been threatened by the smugglers, according to ICE.

An investigation led to the Riverside house, where ICE agents located the relative and 36 others locked in a rear bedroom, where the windows had been boarded up.

The smugglers confiscated the captives' shoes to deter them from running away, officials said.

Another seven illegals linked to the smuggling operation were arrested the same day while being transported into Los Angeles, according to ICE.

"This incident shows, yet again, the ruthlessness and brutality of the smuggling trade," said Claude Arnold, special agent in charge for the Los Angeles ICE office. "Extortion, torture and physical violence are now commonplace in these cases."

The smuggled aliens, who come from the Dominican Republic, Ecuador, El Salvador, Guatemala, Honduras and Mexico, will remain in ICE custody until their cases come under review.