Workers of the Cocola Food factory in Gazipur's Kaliakoir staged a demonstration demanding the implementation of the new wage structure announced by the government.
At least 20 workers were injured in an attack, which was allegedly carried out by throwing brickbats from inside the factory.
The incident took place at around 8:30am on Monday.
Later, the agitated workers blocked the Dhaka-Tangail highway, which caused a long tailback on both sides.
On information, police rushed to the spot and fired tear shells to disperse the workers.
The agitated workers said they did not enter the factory in the morning and took position in front of the main gate demanding implementation of the new wage structure announced by the government.
At that time, at the instruction of the higher officials of the factory, other staff and workers inside threw brickbats at the workers who were protesting outside.
Several workers, requesting anonymity, told this correspondent that they only get Tk6,000 a month. The factory owners did not increase their salaries despite the government’s orders.
Dipak Majumder, additional superintendent of Gazipur industrial police, said: "We tried to disperse the agitating workers for about two hours by promising to talk to the owners. The workers tried to vandalize the factory and blocked the Dhaka-Tangail highway. They also vandalized some vehicles.”
Police were forced to charge batons at one point, he added.
Anisur Rahman, manager (administration) of the factory, said: "Those who protested today (Monday) are not our employees. We have already accepted the demands of the workers and increased their salaries to Tk8,000. Our workers retaliated when outside workers were attacked.”