Over 100 Indian workers have quit their jobs at a Mississippi shipyard protesting alleged 'slave treatment' by their employer after being 'tricked' into coming to the US and are demanding a probe against the firm, which faced similar accusations last year.

The workers, mostly welders and pipe-fitters, alleged they lived 'like pigs in a cage' in a 'work camp' run by Signal International in Pascagoula shipyard.

Signal forced them to live in substandard housing with 24 men crammed into a small room, for which they were charged more than $ 1,000 a month, the workers claimed.

The Indians symbolically threw their hard hats at the company gates as they walked out alleging that it had brought them to the US by promising permanent residency in exchange for $ 20,000 fee. Instead they said they were given 10-month work visa.

Signal International, however, strongly denied the workers' allegations.

"Unfortunately, a few of the workers whom Signal had sponsored for H2B visas and recruited have made baseless and unfounded allegations against Signal concerning their employment and living conditions," it said in a statement.

The workers told local media that they plan to "report themselves to the Department of Justice as victims of trafficking, and demand federal prosecution of Signal."

"For more than one year, hundreds of Indian workers at Signal International have been living like slaves," a former Signal worker Sabulal Vijayan was quoted as saying by ABC.

"Today the workers are coming out to declare their freedom. This trafficking needs to end."  A similar protest was held by nearly 300 Indian workers at the shipyard in March last year, local media reports said.