MUMBAI, India — More than 100 people died Saturday and Sunday in a fire at a garment factory outside Dhaka, Bangladesh, in one of the worst industrial tragedies in that country.

It took firefighters all night to put out the blaze at the factory, Tazreen Fashions, after it started about 7 p.m. on Saturday, a retired fire official said by telephone from Dhaka, the capital. At least 111 people were killed, and scores of workers were taken to hospitals for treatment of burns and smoke inhalation.

“The main difficulty was to put out the fire; the sufficient approach road was not there,” said the retired official, Salim Nawaj Bhuiyan, who now runs a fire safety company in Dhaka. “The fire service had to take great trouble to approach the factory.”

Bangladesh’s garment industry, the second-largest exporter of clothing after China, has a notoriously poor fire safety record. Since 2006, more than 500 Bangladeshi workers have died in factory fires, according to Clean Clothes Campaign, an anti-sweatshop advocacy group in Amsterdam. Experts say many of the fires could have easily been avoided if the factories had taken the right precautions. Many factories are in cramped neighborhoods and have too few fire escapes, and they widely flout safety measures. The industry employs more than three million workers in Bangladesh, most of them women.

Activists say that global clothing brands like Tommy Hilfiger and the Gap and those sold by Walmart need to take responsibility for the working conditions in Bangladeshi factories that produce their clothes.

“These brands have known for years that many of the factories they choose to work with are death traps,” Ineke Zeldenrust, the international coordinator for the Clean Clothes Campaign, said in a statement. “Their failure to take action amounts to criminal negligence.”

In a statement from the United States, Wal-Mart said, “While we are trying to determine if the factory has a current relationship with Walmart or one of our suppliers, fire safety is a critically important area of Walmart’s factory audit program and we have been working across the apparel industry to improve fire safety education and training in Bangladesh.”

The fire at the Tazreen factory in Savar, northwest of Dhaka, started in a warehouse on the ground floor that was used to store yarn, and quickly spread to the upper floors. The building was nine stories high, with the top three floors under construction, according to a garment industry official at the scene who asked not to be named because he was not authorized to speak to the news media. Though most workers had left for the day when the fire started, the industry official said, as many as 600 workers were still inside working overtime.

The factory, which opened in May 2010, employed about 1,500 workers and had sales of $35 million a year, according to a document on the company’s Web site. It made T-shirts, polo shirts and fleece jackets.

Most of the workers who died were on the first and second floors, fire officials said, and were killed because there were not enough exits. “So the workers could not come out when the fire engulfed the building,” said Maj. Mohammad Mahbub, the operations director for the Fire Department, according to The Associated Press.

In a telephone interview later on Sunday, Major Mahbub said the fire could have been caused by an electrical fault or by a spark from a cigarette.

In a brief phone call, Delowar Hossain, the managing director of the Tuba Group, the parent company of Tazreen Fashions, said he was too busy to comment. “Pray for me,” he said and then hung up.

Television news reports showed badly burned bodies lined up on the floor in what appeared to be a government building. The injured were being treated in hallways of local hospitals, according to the reports.

The industry official said that many of the bodies were burned beyond recognition and that it would take some time to identify them.

One survivor, Mohammad Raju, 22, who worked on the fifth floor, said he escaped by climbing out of a third-floor window onto the bamboo scaffolding that was being used by construction workers. He said he lost his mother, who also worked on the fifth floor, when they were making their way down.

“It was crowded on the stairs as all the workers were trying to come out from the factory,” Mr. Raju said. “There was no power supply; it was dark, and I lost my mother in dark. I tried to search for her for 10 to 15 minutes but did not find her.”

A document posted on Tazreen Fashions’ Web site indicated that an “ethical sourcing” official for Walmart had flagged “violations and/or conditions which were deemed to be high risk” at the factory in May 2011, though it did not specify the nature of the infractions. The notice said that the factory had been given an “orange” grade and that any factories given three such assessments in two years from their last audit would not receive any Walmart orders for a year.

A spokesman for Walmart, Kevin Gardner, said the company was “so far unable to confirm that Tazreen is a supplier to Walmart nor if the document referenced in the article is in fact from Walmart.”

But the International Labor Rights Forum, which tracks fires in the Bangladesh garment industry, said documents and logos found in the debris indicated that the factory produced clothes for Walmart’s Faded Glory line as well as for other American and foreign companies.

Bangladesh exports about $18 billion worth of garments a year. Employees in the country’s factories are among the world’s lowest-paid, with entry-level workers making the government-mandated minimum wage of about $37 a month or slightly above.

Tensions have been running high between workers, who have been demanding an increase in minimum wages, and the factory owners and government. A union organizer, Aminul Islam, who campaigned for better working conditions and higher wages, was found tortured and killed outside Dhaka this year.

Julfikar Ali Manik contributed reporting from Dhaka, Bangladesh, and Stephanie Clifford and Steven Greenhouse from New York.