Up to 80% of garment workers in Bangalore, India, are believed to be migrant workers. Many don’t speak the local language and struggle to find housing, so garment factories fill the gap by offering company accommodations. The only catch: Some residents are treated like prisoners.

According to a new report (pdf) by labor rights NGO India Committee of the Netherlands, conditions inside factory “hostels” can be terrible, involving forced confinement and constant surveillance.

Two of the factories singled out in the region, officially known as Bengaluru, supply large fast-fashion chains H&M and C&A. Other factories in the area produce clothing for Gap, Tommy Hilfiger, and Inditex, the owner of Zara. While all of the companies the India Committee (ICN) contacted, except for Gap, responded with promises to take serious action, it’s yet another example of how little large international brands may know about the workers actually making their products.

Most were allowed to leave for only two hours a week.

Among the worst of the findings in the report was that some Bengaluru factories kept women (the majority of garment workers) in hostels monitored by male security guards and severely restricted their movements. Most were allowed to leave for only two hours a week, usually on Sunday to buy groceries and other items, and only after registering with a guard. The rest of the time, women were expected to travel only to and from work, and guards recorded when they arrived at and left the hostels.

The ICN, it’s worth noting, didn’t record these practices at the two factories known to produce for H&M and C&A, though the C&A factory did employ guards. The H&M factory hostel only housed men, and they were allowed out until 11pm.

Workers could use phones to talk with friends and family, but the report points out that they had little to no opportunity to interact with labor advocates, making them more vulnerable to abuses. Indeed, some hostels segregated migrants by region, paying certain groups less. All made at least the minimum wage, though Bengaluru’s garment industry has previously been singled out for its unfairly low wages.

Many of the workers were also afraid of punishment. If a woman returned late, for instance, she could be made to wait outside the gate for hours until a guard let her in.

Many of the workers were also afraid of punishment.

The report found that the hostels generally provide the bare minimum. At a hostel run by Arvind, which supplies H&M, men slept on three-tier bunk beds in large, divided halls. There are no kitchens, the water supply is irregular, and one bathroom serves 12 to 14 people. “Nothing is good,” one Arvind worker said. “But we are staying here because we have to live and there is no other way.” Workers also had to pay to stay there.

Some of the other hostels, including one run by a factory that supplies C&A, offered better conditions and didn’t charge for lodging.

The ICN compiled its report based on desk research, interviews with 110 workers from four different factories, and information from a local labor union.

As the factories wouldn’t allow the ICN into the hostels, they had to do their interviews as workers traveled to and from work. Workers were hesitant to speak with the ICN for fear of retribution. “A lot of things happen, but we cannot talk about it,” one North Indian migrant told the group.

It’s hard to say if the findings represent the industry as a whole. The ICN says there are as many as 1,200 factories in and around Bengaluru, but the findings clearly don’t bode well.

H&M, Inditex, and C&A said they are jointly working with local trade unions to improve conditions. PVH, which owns Tommy Hilfiger, is independently investigating and establishing guidelines for its suppliers.