DHAKA/CHICAGO (Reuters) - Bangladesh said a fire that killed 111 textile workers was sabotage, as protesters took to the streets for a second day on Tuesday and garment factories across the world's second-biggest clothes exporter stopped work to mourn.
Meanwhile two other incidents this week, neither of which caused injuries, had local manufacturing leaders scrambling to assess whether their industry was under attack.
Saturday's fire has put a spotlight on global retailers that source clothes from Bangladesh, where the cost of labor is low - as little as $37 a month for some workers - and rights groups have called on firms to sign up to a fire safety program.
U.S. retailer Sears Holdings Corp said its clothing was not meant to be made in that textile factory, and was investigating reports that one of its brands had been found in the charred debris. Other brands, such as Esprit Holdings Ltd, continued to deny any connection and distanced themselves from the disaster.
The country's worst-ever industrial blaze consumed a multi-story building of a Tazreen Fashions factory. More than 150 workers were injured.
The interior minister, Mohiuddin Khan Alamgir, said that, according to a preliminary inquiry, the fire was the result of arson. He promised to bring the culprits to justice.
"We have come to the conclusion that it was an act of sabotage. We are finding out as of now who exactly the saboteurs are and all culprits will be brought to book," Alamgir said.
Earlier, Prime Minister Sheikh Hasina said she suspected the fire was an act of sabotage, but she did not identify any suspect or say why she thought the cause might have been arson.
Dhaka district police chief Habibur Rahman told Reuters his men were investigating complaints from some survivors that factory managers stopped workers from running out of the building when a fire alarm went off.
In addition to Saturday's blaze, two other incidents outside Dhaka -- a fire at a factory Monday morning and an explosion and fire at a facility Tuesday evening -- had the country's manufacturing leaders scared something bigger was at play.
"If you ask me as to what happened at the factory, today I'm a little confused because having such incidents all around naturally raises questions in the mind," said Annisul Huq, former president of the Bangladesh Garment Manufacturers and Exporters Association, in an interview.
"The government today says they are smelling sabotage. We don't yet know what they mean by that, we will know in a few days. I don't know what information they have but we don't like this link," he said, adding that association members would meet Wednesday to discuss the recent events.
Wal-Mart Stores Inc, the world's largest retailer, said one of its suppliers subcontracted work to the burned factory without authorization and would no longer be used. The company declined additional comment Tuesday on the details of its factory audit program.
Sears also suggested something illicit may have taken place.
"Any merchandise found at that factory should NOT have been manufactured there and we are currently investigating further," the company said in a statement.
The International Labor Rights Forum, in a statement on Sunday, said evidence discovered in the factory suggested Sears' True Desire line may have been manufactured there, as well as other prominent brands.
As of Tuesday afternoon, a petition on Change.org calling on major retailers to join an industry fire safety program for suppliers had more than 22,000 supporters, having roughly doubled in just a few hours.
Representatives of the Tazreen Fashions factory, including the owner, were not available for comment.
Bangladesh has about 4,500 garment factories and is the world's biggest exporter of clothing after China, with garments making up 80 percent of its $24 billion annual exports.
Working conditions at Bangladeshi factories are notoriously poor, with little enforcement of safety laws. Overcrowding and locked fire doors are common.
"There are sometimes very basic issues — having an emergency exit, not being locked in and being able to take bathroom breaks," said Erica Smiley, campaigns director for Jobs with Justice, which works with workers' rights groups in Bangladesh.
"We've known for a long time about conditions in these plants in Bangladesh ... The organizations we work with in Bangladesh had a track of these factories including the (Tazreen) factory," she said.
More than 300 factories near the capital were shut for almost a week earlier this year as workers demanded higher wages and better conditions. At least 500 people have died in garment factory accidents in Bangladesh since 2006, according to fire brigade officials.
More than 1,000 workers, some carrying black flags, demonstrated Tuesday in the Ashulia industrial belt on the outskirts of the capital where the factory is located. They blocked traffic moving on a highway and vowed to avenge the deaths of their colleagues, witnesses said.
"Never shall we give up demands for punishment for those responsible for the tragedy," one worker said.
Reporting by Ruma Paul and Anis Ahmed in Dhaka and Jessica Wohl and Nivedita Bhattacharjee in Chicago; Additional reporting by Anne Marie Roantree in Hong Kong and Dhanya Skariachan in New York; Writing by Ben Berkowitz; Editing by Robert Birsel, Gunna Dickson, Tim Dobbyn and Andrew Hay