Another fire in a Bangladesh garment factory killed several workers on Saturday, sparking fresh calls for investigations into the safety and labor rights of garment producers in factories that commonly export products to U.S. companies such as Walmart and Walt Disney.

The fire Saturday, which occurred at the Smart Export Garment Ltd. factory, killed seven female workers, an official said Sunday.

"When I tried to escape through the emergency exit I found the gate locked," Raushan Ara, a worker at the factory, told newspaper Prothom Alo.

Local reports said at least 50 people were injured in a stampede triggered by the fire. Several of the injured jumped out of the windows of the two-story factory, survivors said. Roughly 250 workers were in the factory at the time of the fire.

In November, a similar fire killed at least 112 workers in another garment factory near the capital—a record setting disaster in which all of the exits were locked with metal gates. The fire sparked international outrage and a call for tougher regulations on both factory owners and the international corporations which exploit their cheap labor.

Government official Jahangir Kabir Nanak said an investigation has been ordered into the cause of Saturday's fire and allegations that the emergency exit was locked.

Altaf Hossain, father of a garment worker killed on Saturday, has filed a police case against the three directors of the factory, accusing them of negligence involving the fire, Dhaka Metropolitan Police Sub-inspector Shamsul Hoque told The Associated Press on Sunday.

It was not immediately reported which, if any, international companies were in business with the factory.

However, in response to the fire and the likelihood that western corporations will be implicated in the disaster, on Sunday International labor rights groups called for global clothing retailers to ensure adequate safety measures for garment workers in Bangladesh, asking retailers and brands to sign a fire safety agreement with Bangladesh.

"After more than two decades of the apparel industry knowing about the risks to these workers, nothing substantial has changed," the Executive Director of the International Labor Rights Forum, Judy Gearhart, said in a statement issued along with The Worker Rights Consortium (WRC) and the Clean Clothes Campaign (CCC).

"Brands still keep their audit results secret. They still walk away when it suits them and trade unions are still marginalized, weakening workers' ability to speak up when they are at risk," she added.