Police in Bangladesh have arrested three supervisors from a clothing factory in which more than 100 people died during a fire.
They say the supervisors are accused of stopping workers from leaving the building and of padlocking exits.
Meanwhile, thousands of garment workers staged fresh protests outside Dhaka, demanding higher safety standards.
Government officials say preliminary information suggests the fire was an act of sabotage.
The government has opened two inquiries.
Police say the supervisors told panicked workers at the Tazreen Fashion factory that the fire on Saturday night was just a drill and they had nothing to worry about.
"All three are mid-level managers of Tazreen. Survivors told us they did not allow the workers to escape the fire, saying it was a routine fire drill," city police chief Habibur Rahman told AFP news agency.
"There are also allegations that they even padlocked doors," he added.
On Wednesday, police fired rubber bullets and tear gas to disperse thousands of workers in the Ashulia industrial area, just outside the Bangladeshi capital.
"We were forced to react as they started pelting officers with stones," local police official Moktar Hossain said.
The BBC's Anbarasan Ethirajan in Dhaka says there has been growing public anger over the fire, and the industrial suburbs around the capital are tense.
Many factories have declared Wednesday a holiday fearing large-scale labour unrest.
Some workers also vandalised factories and set fire to motorcycles, injuring at least 20 people, the online edition of the Daily Star reported.
On Tuesday, Bangladesh declared a day of mourning for the victims.
The burnt-out nine-storey factory supplied clothes to a variety of international brands including US retail giant Walmart.
Walmart says the factory had been sub-contracted without its knowledge. It said it was cutting ties with its supplier without naming the firm.
Labels from the European chain C&A, Hong Kong's Li & Fung and the US rapper and actor Sean "Diddy" Combs were also found in the factory.
The clothing industry is the backbone of the Bangladeshi economy, with exports last year alone worth more than $19bn (£12bn).
Fatal fires are common in Bangladesh's garment sector with lax safety standards, poor wiring and overcrowding blamed for causing several blazes every year.