Dhaka, Bangladesh (CNN) -- At least 11 people were killed and scores others injured when an under-construction overpass collapsed in southeastern Bangladesh, police said Sunday.
"We've recovered 11 bodies so far, and the death toll may rise further as the rescuers are yet to remove the rubble of the girders of the flyover, which collapsed Saturday night," said Mirazuddin Ahmed, deputy commissioner of Chittagong Metropolitan Police.
Police said about 20 people remained trapped after three concrete beams of the overpass -- each 42 meters long -- collapsed in Bangladesh's second-largest city.
Outrage over the collapse spread quickly. Hundreds of protesters took to the streets, with some setting fire to vehicles and a police outpost, police and witnesses said.
Protesters attacked a fire engine, alleging that fire units came late. They also torched a makeshift office of the construction firm and its equipment.
Police fired tear gas and used batons to disperse angry protesters.
Army troops joined the rescue operation after firefighters had difficulty reaching the area due to the throngs of protesters.