Garment workers in Bangladesh have held a second day of demonstrations, as the country observed a day of mourning for at least 110 people killed in a Saturday factory fire.

About 1,000 workers, many carrying black flags, demanded justice for the victims as they protested Tuesday on the outskirts of the capital, Dhaka.

Factories were closed and flags at government buildings flew at half-staff to honor those who died when hundreds of workers were trapped in the fire at the Tazreen Fashion factory.

Home Minister Mohiuddin Khan Alamgir toured the site Tuesday, and said that a preliminary investigation pointed to sabotage as a cause of the blaze.

“Prime Minister Sheikh Hasina already announced it in the parliament yesterday. We are finding out as of now who exactly the saboteurs are, and we are determined that these saboteurs are brought to book.”

Fire officials say a lack of emergency exits contributed to the deaths, with many workers jumping out of the multi-story building after being trapped in the blaze.

U.S. retailer Walmart said the factory was not authorized to produce its merchandise, but that one of its suppliers had subcontracted work at the site without the company's approval. A Walmart statement Monday said the company has terminated business with that supplier.

European chain C&A and Hong Kong-based Li & Fung have also said some of their products were made at the Tazreen factory.

Bangladesh has about 4,000 garment factories that make clothes for international brands. The country earns about $20 billion annually from overseas clothing sales, roughly 80 percent of its exports.

Work conditions at the country's garment factories are notoriously poor. Officials say at least 500 people have died in Bangladesh in garment factory accidents and fires since 2006. Activists say plant owners are rarely prosecuted for poor safety conditions.