DHAKA: Bangladeshi police hunted a fugitive factory boss on Tuesday after claims that workers making cheap clothes for Western firms including Walmart were told that an alarm for a deadly fire was a routine drill.

About 1,000 workers took part in a second day of demonstrations against dangerous factory conditions as the country held a national day of mourning for the 110 killed in the inferno.

Green and red Bangladeshi flags flew at half mast alongside black flags on top of government offices and the nation’s 4,500 garment factories.

Two government inquiries have already been set up to try to establish the cause of the fire, which broke out on Saturday at the Tazreen factory 30 kilometers outside the capital Dhaka.

It was the worst ever fire to hit Bangladesh’s garment industry, which employs three million and is the mainstay of the poverty-stricken country’s economy.

Dhaka police Chief Habibur Rahman said that officers wanted to interrogate Tazreen’s owner Delwar Hossain about alleged violations of building rules, after inspectors found the nine-storey factory only had permission for three floors.

Police had opened a murder investigation as a result of criminal negligence at the plant, Rahman added. “We have launched a search for the owner and the managers but so far we have not been able to trace them.”

The search was launched as a fresh protest was held in the Ashulia industrial area, home to about 500 factories who sew clothing for global retailers.

Witnesses said that about 1,000 workers took part in the march, holding black flags and chanting slogans demanding justice for the victims as well as denouncing the “death trap” working conditions.

On Monday several thousand workers held marches in Ashulia demanding Hossain’s arrest.

Bangladesh is the world’s second largest clothes exporter with overseas garment sales topping $19 billion last year or 80 percent of national exports. Forty percent of Bangladesh’s industrial workforce is employed in the sector but conditions are often basic and safety standards low.

Around 700 garment workers have been killed in dozens of fires since 2006, according to the Clean Clothes Campaign, an Amsterdam-based textile rights group.

But none of the owners so far have faced prosecution for poor safety conditions. Campaigners said that Western firms, whose clothes are made in Bangladesh, hide behind flimsy safety audits to help drive down costs.