Thousands of workers protested for a third day Wednesday after Bangladesh's worst garment factory fire as police arrested three managers over claims they stopped employees from leaving the burning plant.

At least 5,000 workers left their factories and joined the protests, pelting plants with stones and streaming through the main streets of Ashulia industrial area, just outside Dhaka and home to 500 manufacturing outlets, police said.

"They were demanding justice for the fire victims and arrest of the Tazreen owner," Faruq Ahmed, a senior Dhaka police official said.

Ahmed was referring to the garment factory in Ashulia where a weekend blaze left at least 110 people dead and more than 100 injured.

Police fired hot water from a water cannon to disperse the crowd while more than 100 factories declared an impromptu holiday for the day, fearing the protests would spread into larger-scale industrial unrest.

Police have arrested three managers of the factory hit by the weekend fire, following charges that they stopped workers from leaving the plant by insisting that an alarm was just a routine fire drill.

Dhaka police chief Habibur Rahman  said the managers allegedly told panicked workers they had nothing to worry about when the fire started on Saturday night.

"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. There are also allegations they even padlocked doors," Rahman said.