At least 50 locals were later injured in a clash with the police when they prevented the law enforcers from taking the dead bodies to hospital for autopsy.

The dead are Sanwar Hossain, 28, Keramat Ali, 30, and Rahman Ali, 28--all caretakers of shanties at Rayerbazar living at Sultanganj of the same area.

Locals said five caretakers, including the three, got down into the sewer at Sanatangarh of Boubazar area under the Hazaribagh Police Station to clean it at 10:00am after failing to clean the clogged wastes with bamboo sticks.

"As there was no sign of them, some of us peeped through the manhole and found them lying inside," said a rescuer.

Sanwar and Keramat died on the spot while Rahman fell critically ill from poisonous gas inhalation. He was rushed to Sikder Medical College and Hospital where doctors declared him dead.

The police went to the spot at around 2:00pm to take the bodies to morgue for autopsy, but the locals prevented them. At one point, some 300 locals locked into a clash with the cops and around 50 were injured, the locals claimed.

The police later sent the bodies of Sanwar and Keramat to the Mitford Hospital morgue and the body of Rahman to the Dhaka Medical College morgue.

The locals alleged that three days ago they went to Commissioner Jasim Uddin of ward No. 47 of Dhaka City Corporation regarding cleaning of the clogged wastes.

"The commissioner refused to do it," said Kanchan Khan, a resident of the area. "He told us to leave our houses when we pleaded that it became intolerable to live amid the stink of the toxic wastes," he added.

Commissioner Jasim, however, denied the allegation and told The Daily Star that he sought time from the locals saying he would inform the government of the situation. He advised the locals to live somewhere else since the toxic gas might harm the children, he added.