Hundreds of people were arrested in the United States in 2012 as authorities crack down on "the evil" of human trafficking, US officials said Friday, warning modern-day slaves could be hidden in any neighborhood.

Around the world some 27 million people, including women and girls, are the victims of trafficking, US Secretary of State John Kerry said as he chaired an inter-agency White House meeting on trafficking.

He had been "stunned by the stories and examples of the evil... It is nothing less than the most predatory, extraordinary modern slavery that you can conceivably imagine."

But such "degradation and depravity" is not just happening in far flung corners of the world such as Africa or Asia, he warned.

Just earlier this month three young women were rescued from a house in Ohio where they had been held for a decade, Kerry recalled.

Human trafficking "tears apart communities, tears apart families, challenges rule of law, not to mention that it is a moral obscenity," Kerry added at the meeting to review progress on what he called an "unprecedented" government effort to end trafficking and help the victims.

US Immigration and Customs Enforcement made more than 950 arrests for trafficking offenses in 2012, rescued some 300 people and won over 380 convictions -- more than double the 144 in 2010.

And a special hotline set up for victims received more than 20,000 calls last year, a 74 percent increase on two years ago.

But officials admitted it was not known for sure how many trafficking victims had been hidden away across the United States.

"Human trafficking is really a hidden crime, and Cleveland just indicates again to all of us the nature of that," said Rand Beers, acting deputy secretary of the Department of Homeland Security.

He pointed to the labor market, sex trafficking and domestic servitude as the three areas that "we need people to begin to think about in their every day lives" and help shed light on the victims.